United States v. Anthony Loring - Mr. Mermelstein's classes

PRINCETON UNIVERSITY
HIGH SCHOOL MOOT COURT COMPETITION
Spring 2012 DOCKET
United States
v.
Anthony Loring
Supreme Court of the United States
Oral Argument Scheduled for April 2012
Updated 3/9/12

Fact Pattern
Updated 3/9/12
At 5:00 PM on April 2, 2010, the FBI learned from confidential informant Kristen McCarthy that
notorious gang leader Anthony Loring would be transporting a large quantity of C-4 explosives
from Portland, ME to Princeton, NJ sometime later that evening. McCarthy informed the police
that Loring contacted her with the intention of borrowing her car, a Mercedes SLK Roadster, to
transport the explosives. McCarthy described the car as being black with dark tinted windows,
and identified that Loring wanted to use this specific car because of the presence of the tinted
windows. McCarthy informed the police that just prior to the phone call she had given Loring the
keys to her car, and that she was unsure of the route that Loring would take to get from Portland
to Princeton or what time he would be leaving.
Upon learning this information, Dana Weinstein of the Federal Bureau of Investigation
immediately contacted the United States Mercedes National Headquarters with regards to the
Roadster’s in-car global positioning satellite unit. Specifically, Weinstein was hoping to use the
Roadster’s in-car navigation system to track the car’s location as it traveled from Portland to
Princeton. Because the car receives information from a number of satellites, Weinstein was
hoping that the representatives from the Mercedes would be able to intercept the signal being
sent to the Roadster’s in-car GPS in order to track and determine the Roadster’s exact location as
it traveled from Portland to Princeton. Mercedes representatives provided Weisntein with access
to the GPS unit associated with the Roadster, and Weinstein was able to successfully track the
vehicle. the car’s location, Exit 130 on the Garden State Parkway.
Weinstein and her team of FBI investigators tracked the Roadster and pulled Loring over as he
merged on to Route 1 from the Garden State Parkway during the early hours of the morning on
April 3. The only way Weinstein and her team were able to locate the Roadster was using the
car’s built in navigation system. Police cars surrounded the vehicle, and Weinstein approached
the driver’s side door, weapon drawn, and ordered Loring exit the vehicle. Loring exited the
vehicle, locked the car, and was immediately handcuffed by Weinstein. Weinstein asked Loring
if he had any explosive devices in the car and he told her he did not. Weinstein then ordered that
Loring be frisked to search for any potential weapons. The frisking revealed that Loring was
carrying a Motorola Razr and the car keys to the Roadster. Herrera took Loring’s keys and
opened the trunk of the car with the intent of searching for the C-4 Loring was known to be
transporting.
Upon opening the trunk Weinstein discovered four tied, translucent garbage bags. Unable to see
their contents, she pulled all four of the trash bags out the car and placed them on the roadway.
She opened the trash bags carefully and deliberately and discovered that the four bags contained
large quantities of cash, totaling approximately 8 million dollars. Loring was subsequently
arrested and charged with 18 U.S.C. § 1956 for laundering money.
Loring was indicted by a grand jury 2 weeks later, and a trial date was set for June 5, 2010. Prior
to trial, Loring, who had decided to go pro se, made a motion to dismiss the charges based on
two grounds. First, Loring contended that the initial use of the GPS to track the vehicle
constituted an unlawful search of the vehicle under the Fourth Amendment. Second, because the
initial search of the vehicle was unlawful, Loring further contended that any fruits of the search,

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the bags of money, were not admissible in court. Loring also argued that if the court did find that
the search was constitutionally cognizable, then the fruits of the search were still inadmissible
because Weinstein did not have the necessary judicial notice in the form of a warrant to search
the vehicle, and because she was searching under that the pretense that Loring was carrying
explosives made any evidence gleaned from the search inadmissible.
In response, the federal prosecutor Oren Samet argued that that the use of the GPS to track the
car did not constitute a search. However, in the case that the court did find that the search was in
fact constitutionally cognizable, Samet argued that previous documentation was not needed to
authorize the search because of the presence of exigent circumstances. Samet then cited that
because the evidence, the C-4, was likely to be destroyed and posed a grave risk of danger to
others when she conducted the search that requirement for a warrant was waived. Therefore, the
evidence received from the search of the car was admissible.
Federal Court Judge Alex Peerman ruled that the fruits of the search were admissible. Judge
Peerman divided the search on the Roadster into two parts; the use of the GPS to track the car,
and the physical search of the car itself. Judge Peerman found that the use of the GPS to reverse
track the Mercedes did not constitute a constitutionally cognizable search. He first cited
precedent established by US v. Katz (1967), which claimed that search or seizure occurred if any
individual’s basic right to privacy was violated. He then made use of US v. Knotts (1983), which
cited previous cases that held that there was a reduced expectation of privacy in a motor vehicle.
Judge Peerman also felt that no search occurred because there was no reasonable expectation of
privacy because the car was borrowed, a concept set forth in US v. Karo (1984). Finally, Judge
Peerman cited the court’s recent decision in US v. Jones (2012), which held that that the
placement of a GPS device on the car constituted a search. Because not placement of a GPS
device occurred, Weinstein’s use of the in-car GPS system was not a search.
Judge Peerman did find that the physical search of the car did constitute a constitutionally
cognizable search, and that there were exigent circumstances present that waived the requirement
for a warrant, making the fruits of the search admissible. He first cited the nature of exigent
circumstances set forth by a case from the 9 th Circuit Court of Appeals US v. McConney (1984).
He identified the key issue associated with exigent circumstances, that the court must weigh the
“risk police officers can reasonably be expected to assume before disregarding the rules society
has adopted to otherwise circumscribe the exercise of their considerable discretionary authority
in carrying out their vital law enforcement duties.” Specifically, Judge Peerman stated that
Loring’s status as a known gang leader, and the nature of item being searched, C-4, put the
agents at the scene in a reasonable danger of being harmed and also posed the risk that the
evidence, the dynamite itself, would be destroyed. Judge Peerman held that we could not blame
the agents for the fact that the items being transported were not what they appeared to be;
instead, he cited that Weinstein acted to the best of her abilities based on the limited information
they had and decided that they acted in the interest of justice, and so the evidence should be
admissible in court.
Loring was subsequently found guilty. He then appealed the ruling on the admissibility of the
evidence of the search to the 3 rd Circuit of the US Court of Appeals and received a more
favorable response.

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Judge Katy Herrera first found that the used of the GPS device inside the Roadster constituted a
constitutionally cognizable search. She then found that there were no exigent circumstances in
place that did waive the warrant requirement in either the search that was performed when
tracking the car using the GPS or the physical search of the car itself.
Judge Herrera first found that the search was constitutionally cognizable. She cited the precedent
established in US v. Katz (1967) that established the basic right to privacy, and she found that
because Loring had requested the use of the Roadster from McCarthy that possessed tinted
windows, he assumed a reasonable expectation of privacy with regards to the vehicle.
Furthermore, she found that the government’s request of Mercedes to use the car’s GPS device to
track the car’s movements demonstrated that the government “physically occupied the private
property of a person for the purpose of obtaining information,” a precedent established in the
court’s recent decision of US v. Jones (2012). Judge Herrera also made a unique interpretation of
US v. Knotts, citing that due to the specific nature of these facts, Loring’s actions did not reduce
the reasonable expectation of privacy one usually assumes when driving a vehicle. She cited the
fact that Loring requested a different car, one known to be fast, a vehicle with tinted windows
and the fact that Loring planned to drive at night as reasons why there was a reasonable
expectation of privacy in this case, one that was violated by the FBI.
Judge Herrera then found that there were no exigent circumstances present that allowed for such
either search to be conducted without a warrant. Herrera cited the precedent of a case from the
9 th Circuit Court of Appeals US v. McConney (1984) that dealt with the issue of the
establishment of exigent circumstances. She cited the fact that because no remote detonator was
found on Loring’s person during a search and there were no physical indicators that the agents
were in any grave danger by standing near the car meant no exigent circumstances were present.
Even further, Judge Herrera cited how even if the agents felt they were in reasonable danger, the
fact that there were no bombs in plain view should have caused Herrera to stop the search and
retrieve a warrant, citing the plain view doctrine of Horton v. California (1990).
Upon this ruling, Loring’s conviction was reversed. The decision was appealed by the United
States, and is to be argued before the Supreme Court in April 2012.
In argument, you will either assume the role of the attorneys for the petitioner, the United States,
or the respondent, Anthony Loring. Engage the critical issues and make recommendations for the
constitutionally proper resolution of the case. You should make reference to both the
Constitution and relevant precedents. The only case law that can be sided is provided below.
Although other cases may be cited in the context of the selections, these cases may not be
referenced in the course of argument. Referring to any other case-law or study beyond what is
directly provided will constitute a violation of tournament rules.

Updated 3/9/12
Supreme Court of the United States
The United States,
Petitioner
v.
Mr. Anthony Loring,
Respondent
--------------
Spring 2012 Docket
--------------
On Writ of Certiorari to the
Third Circuit Court of Appeals
ORDER OF THE COURT ON SUBMISSION
After considering the written briefs of both parties and the record of the Third
Circuit Court of Appeals, this court finds that resolution of the case rests upon
review of statutory and constitutional materials.
It is therefore ordered that counsel present oral argument on the following
questions:
1) Does the use of an in-car GPS device in a suspect's motor-vehicle constitute a
constitutionally cognizable search under the Fourth Amendment and therefore
require the presence of exigent circumstances to constitutionalize the search in the
absence of prior judicial certification?
2) If the fruits of the search have nothing to do with the alleged exigent
circumstances that justified departure from the warrant requirement of the Fourth
Amendment according to the first question, and, indeed, nothing at all to do with
exigency, then should the evidence gained from the search be excluded or admitted
at trial?

Relevant Constitutional Provisions
Updated 3/9/12
Preamble
We the People of the United States, in Order to form a more perfect Union, establish Justice,
insure domestic Tranquility, provide for the common defence, promote the general Welfare, and
secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this
Constitution for the United States of America.
Article III, Section 1
The judicial Power of the United States shall be vested in one supreme Court, and in such
inferior Courts as the Congress may from time to time ordain and establish. The Judges, both of
the supreme and inferior Courts, shall hold their Offices during good Behaviour, and shall, at
stated Times, receive for their Services a Compensation, which shall not be diminished during
their Continuance in Office.
Fourth Amendment
The right of the people to be secure in their persons, houses, papers, and effects, against
unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon
probable cause, supported by Oath or affirmation, and particularly describing the place to be
searched, and the persons or things to be seized.
Comment: Competitors may reference any section of the Constitution, including its
amendments. The above sections are merely highlighted for convenience. Competitors may
reference any piece of the constitutional text that they find useful.

Relevant Case Law
KATZ V. UNITED STATES, 389 U. S. 347 (1967)
Syllabus
Updated 3/9/12
Petitioner was convicted under an indictment charging him with transmitting wagering
information by telephone across state lines in violation of 18 U.S.C. 1084. Evidence of
petitioner's end of the conversations, overheard by FBI agents who had attached an electronic
listening and recording device to the outside of the telephone booth from which the calls were
made, was introduced at the trial. The Court of Appeals affirmed the conviction, finding that
there was no Fourth Amendment violation since there was "no physical entrance into the area
occupied by" petitioner.
Held:
1) The Government's eavesdropping activities violated the privacy upon which petitioner
justifiably relied while using the telephone booth, and thus constituted a "search and seizure"
within the meaning of the Fourth Amendment.
a) The Fourth Amendment governs not only the seizure of tangible items, but extends as
well to the recording of oral statements.
b) Because the Fourth Amendment protects people, rather than places, its reach cannot
turn on the presence or absence of a physical intrusion into any given enclosure. The
"trespass" doctrine is no longer controlling.
2. Although the surveillance in this case may have been so narrowly circumscribed that it could
constitutionally have been authorized in advance, it was not in fact conducted pursuant to the
warrant procedure which is a constitutional precondition of such electronic surveillance.
MR. JUSTICE STEWART delivered the opinion of the Court.
The petitioner was convicted in the District Court for the Southern District of California under an
eight-count indictment charging him with transmitting wagering information by telephone from
Los Angeles to Miami and Boston, in violation of a federal statute. At trial, the Government was
permitted, over the petitioner's objection, to introduce evidence of the petitioner's end of
telephone conversations, overheard by FBI agents who had attached an electronic listening and
recording device to the outside of the public telephone booth from which he had placed his calls.
In affirming his conviction, the Court of Appeals rejected the contention that the recordings had
been obtained in violation of the Fourth Amendment, because "there was no physical entrance
into the area occupied by the petitioner." We granted certiorari in order to consider the
constitutional questions thus presented.
The petitioner has phrased those questions as follows:

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"A. Whether a public telephone booth is a constitutionally protected area so that evidence
obtained by attaching an electronic listening recording device to the top of such a booth is
obtained in violation of the right to privacy of the user of the booth. "
"B. Whether physical penetration of a constitutionally protected area is necessary before
a search and seizure can be said to be violative of the Fourth Amendment to the United
States Constitution."
We decline to adopt this formulation of the issues. In the first place, the correct solution of
Fourth Amendment problems is not necessarily promoted by incantation of the phrase
"constitutionally protected area." Secondly, the Fourth Amendment cannot be translated into a
general constitutional "right to privacy." That Amendment protects individual privacy against
certain kinds of governmental intrusion, but its protections go further, and often have nothing to
do with privacy at all. Other provisions of the Constitution protect personal privacy from other
forms of governmental invasion. But the protection of a person's general right to privacy -- his
right to be let alone by other people -- is, like the protection of his property and of his very life,
left largely to the law of the individual States.
Because of the misleading way the issues have been formulated, the parties have attached great
significance to the characterization of the telephone booth from which the petitioner placed his
calls. The petitioner has strenuously argued that the booth was a "constitutionally protected
area." The Government has maintained with equal vigor that it was not. But this effort to decide
whether or not a given "area," viewed in the abstract, is "constitutionally protected" deflects
attention from the problem presented by this case. For the Fourth Amendment protects people,
not places. What a person knowingly exposes to the public, even in his own home or office, is
not a subject of Fourth Amendment protection. But what he seeks to preserve as private, even in
an area accessible to the public, may be constitutionally protected.
The Government stresses the fact that the telephone booth from which the petitioner made his
calls was constructed partly of glass, so that he was as visible after he entered it as he would have
been if he had remained outside. But what he sought to exclude when he entered the booth was
not the intruding eye -- it was the uninvited ear. He did not shed his right to do so simply because
he made his calls from a place where he might be seen. No less than an individual in a business
office, in a friend's apartment, or in a taxicab, a person in a telephone booth may rely upon the
protection of the Fourth Amendment. One who occupies it, shuts the door behind him, and pays
the toll that permits him to place a call is surely entitled to assume that the words he utters into
the mouthpiece will not be broadcast to the world. To read the Constitution more narrowly is to
ignore the vital role that the public telephone has come to play in private communication.
The Government contends, however, that the activities of its agents in this case should not be
tested by Fourth Amendment requirements, for the surveillance technique they employed
involved no physical penetration of the telephone booth from which the petitioner placed his
calls. It is true that the absence of such penetration was at one time thought to foreclose further
Fourth Amendment inquiry, for that Amendment was thought to limit only searches and seizures
of tangible property. But "the premise that property interests control the right of the Government
to search and seize has been discredited." Thus, although a closely divided Court supposed

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in Olmstead that surveillance without any trespass and without the seizure of any material object
fell outside the ambit of the Constitution, we have since departed from the narrow view on which
that decision rested. Indeed, we have expressly held that the Fourth Amendment governs not
only the seizure of tangible items, but extends as well to the recording of oral statements,
overheard without any "technical trespass under . . . local property law." Once this much is
acknowledged, and once it is recognized that the Fourth Amendment protects people -- and not
simply "areas" -- against unreasonable searches and seizures, it becomes clear that the reach of
that Amendment cannot turn upon the presence or absence of a physical intrusion into any given
enclosure.
We conclude that the underpinnings of [the trespass doctrine] have been so eroded by our
subsequent decisions that the "trespass" doctrine there enunciated can no longer be regarded as
controlling. The Government's activities in electronically listening to and recording the
petitioner's words violated the privacy upon which he justifiably relied while using the telephone
booth, and thus constituted a "search and seizure" within the meaning of the Fourth Amendment.
The fact that the electronic device employed to achieve that end did not happen to penetrate the
wall of the booth can have no constitutional significance.
The question remaining for decision, then, is whether the search and seizure conducted in this
case complied with constitutional standards. In that regard, the Government's position is that its
agents acted in an entirely defensible manner: they did not begin their electronic surveillance
until investigation of the petitioner's activities had established a strong probability that he was
using the telephone in question to transmit gambling information to persons in other States, in
violation of federal law. Moreover, the surveillance was limited, both in scope and in duration, to
the specific purpose of establishing the contents of the petitioner's unlawful telephonic
communications. The agents confined their surveillance to the brief periods during which he
used the telephone booth, and they took great care to overhear only the conversations of the
petitioner himself.
Accepting this account of the Government's actions as accurate, it is clear that this surveillance
was so narrowly circumscribed that a duly authorized magistrate, properly notified of the need
for such investigation, specifically informed of the basis on which it was to proceed, and clearly
apprised of the precise intrusion it would entail, could constitutionally have authorized, with
appropriate safeguards, the very limited search and seizure that the Government asserts, in fact,
took place. Only last Term we sustained the validity of such an authorization, holding that, under
sufficiently "precise and discriminate circumstances," a federal court may empower government
agents to employ a concealed electronic device "for the narrow and particularized purpose of
ascertaining the truth of the . . . allegations" of a "detailed factual affidavit alleging the
commission of a specific criminal offense." Discussing that holding, the Court in Berger v. New
York, , said that "the order authorizing the use of the electronic device" in Osborn "afforded
similar protections to those . . . of conventional warrants authorizing the seizure of tangible
evidence." Through those protections, "no greater invasion of privacy was permitted than was
necessary under the circumstances." Id. at . Here, too, a similar judicial order could have
accommodated "the legitimate needs of law enforcement" by authorizing the carefully limited
use of electronic surveillance.

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The Government urges that … because they did no more here than they might properly have
done with prior judicial sanction, we should retroactively validate their conduct. That we cannot
do. It is apparent that the agents in this case acted with restraint. Yet the inescapable fact is that
this restraint was imposed by the agents themselves, not by a judicial officer. They were not
required, before commencing the search, to present their estimate of probable cause for detached
scrutiny by a neutral magistrate. They were not compelled, during the conduct of the search
itself, to observe precise limits established in advance by a specific court order. Nor were they
directed, after the search had been completed, to notify the authorizing magistrate in detail of all
that had been seized. In the absence of such safeguards, this Court has never sustained a search
upon the sole ground that officers reasonably expected to find evidence of a particular crime and
voluntarily confined their activities to the least intrusive means consistent with that end. Searches
conducted without warrants have been held unlawful "notwithstanding facts unquestionably
showing probable cause," Agnello v. United States, for the Constitution requires "that the
deliberate, impartial judgment of a judicial officer . . . be interposed between the citizen and the
police. . . ."… "Over and again, this Court has emphasized that the mandate of the Fourth
Amendment requires adherence to judicial processes," and that searches conducted outside the
judicial process, without prior approval by judge or magistrate, are per se unreasonable under the
Fourth Amendment -- subject only to a few specifically established and well delineated
exceptions.
It is difficult to imagine how any of those exceptions could ever apply to the sort of search and
seizure involved in this case. Even electronic surveillance substantially contemporaneous with an
individual's arrest could hardly be deemed an "incident" of that arrest. Nor could the use of
electronic surveillance without prior authorization be justified on grounds of "hot pursuit." And,
of course, the very nature of electronic surveillance precludes its use pursuant to the suspect's
consent.
…
MR. JUSTICE BLACK, dissenting.
If I could agree with the Court that eavesdropping carried on by electronic means (equivalent to
wiretapping) constitutes a "search" or "seizure," I would be happy to join the Court's opinion For
on that premise, my Brother STEWART sets out methods in accord with the Fourth Amendment
to guide States in the enactment and enforcement of laws passed to regulate wiretapping by
government. In this respect, today's opinion differs sharply from Berger v. New York, , decided
last Term, which held void on its face a New York statute authorizing wiretapping on warrants
issued by magistrates on showings of probable cause. The Berger case also set up what appeared
to be insuperable obstacles to the valid passage of such wiretapping laws by States. The Court's
opinion in this case, however, removes the doubts about state power in this field and abates to a
large extent the confusion and near-paralyzing effect of the Berger holding. Notwithstanding
these good efforts of the Court, I am still unable to agree with its interpretation of the Fourth
Amendment.
My basic objection is two-fold: (1) I do not believe that the words of the Amendment will bear
the meaning given them by today's decision, and (2) I do not believe that it is the proper role of

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this Court to rewrite the Amendment in order "to bring it into harmony with the times," and thus
reach a result that many people believe to be desirable.
While I realize that an argument based on the meaning of words lacks the scope, and no doubt
the appeal, of broad policy discussions and philosophical discourses on such nebulous subjects as
privacy, for me, the language of the Amendment is the crucial place to look in construing a
written document such as our Constitution. The Fourth Amendment says that
"The right of the people to be secure in their persons, houses, papers, and effects, against
unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but
upon probable cause, supported by Oath or affirmation, and particularly describing the
place to be searched and the persons or things to be seized."
The first clause protects "persons, houses, papers, and effects against unreasonable searches and
seizures. . . ." These words connote the idea of tangible things with size, form, and weight, things
capable of being searched, seized, or both. The second clause of the Amendment still further
establishes its Framers' purpose to limit its protection to tangible things by providing that no
warrants shall issue but those "particularly describing the place to be searched, and the persons
or things to be seized." A conversation overheard by eavesdropping, whether by plain snooping
or wiretapping, is not tangible and, under the normally accepted meanings of the words, can
neither be searched nor seized. In addition the language of the second clause indicates that the
Amendment refers not only to something tangible so it can be seized, but to something already in
existence, so it can be described. Yet the Court's interpretation would have the Amendment
apply to overhearing future conversations, which, by their very nature, are nonexistent until they
take place. How can one "describe" a future conversation, and, if one cannot, how can a
magistrate issue a warrant to eavesdrop one in the future? It is argued that information showing
what is expected to be said is sufficient to limit the boundaries of what later can be admitted into
evidence; but does such general information really meet the specific language of the
Amendment, which says "particularly describing"? Rather than using language in a completely
artificial way, I must conclude that the Fourth Amendment simply does not apply to
eavesdropping.
Tapping telephone wires, of course, was an unknown possibility at the time the Fourth
Amendment was adopted. But eavesdropping (and wiretapping is nothing more than
eavesdropping by telephone) was, as even the majority opinion in Berger, supra, recognized:
"an ancient practice which, at common law, was condemned as a nuisance. 4 Blackstone,
Commentaries 168. In those days, the eavesdropper listened by naked ear under the eaves
of houses or their windows, or beyond their walls seeking out private discourse."
388 U.S. at .
There can be no doubt that the Framers were aware of this practice, and, if they had desired to
outlaw or restrict the use of evidence obtained by eavesdropping, I believe that they would have
used the appropriate language to do so in the Fourth Amendment. They certainly would not have
left such a task to the ingenuity of language-stretching judges. No one, it seems to me, can read
the debates on the Bill of Rights without reaching the conclusion that its Framers and critics well

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knew the meaning of the words they used, what they would be understood to mean by others,
their scope and their limitations. Under these circumstances, it strikes me as a charge against
their scholarship, their common sense and their candor to give to the Fourth Amendment's
language the eavesdropping meaning the Court imputes to it today.
I do not deny that common sense requires, and that this Court often has said, that the Bill of
Rights' safeguards should be given a liberal construction. This principle, however, does not
justify construing the search and seizure amendment as applying to eavesdropping or the
"seizure" of conversations. The Fourth Amendment was aimed directly at the abhorred practice
of breaking in, ransacking and searching homes and other buildings and seizing people's personal
belongings without warrants issued by magistrates. The Amendment deserves, and this Court has
given it, a liberal construction in order to protect against warrantless searches of buildings and
seizures of tangible personal effects. But, until today, this Court has refused to say that
eavesdropping comes within the ambit of Fourth Amendment restrictions. See, e.g., Olmstead v.
United States, (1928), and Goldman v. United States, (1942).
So far, I have attempted to state why I think the words of the Fourth Amendment prevent its
application to eavesdropping. It is important now to show that this has been the traditional view
of the Amendment's scope since its adoption, and that the Court's decision in this case, along
with its amorphous holding in Berger last Term, marks the first real departure from that view.
The first case to reach this Court which actually involved a clear-cut test of the Fourth
Amendment's applicability to eavesdropping through a wiretap was, of course, Olmstead,
supra. In holding that the interception of private telephone conversations by means of
wiretapping was not a violation of the Fourth Amendment, this Court, speaking through Mr.
Chief Justice Taft, examined the language of the Amendment and found, just as I do now, that
the words could not be stretched to encompass overheard conversations:
…
Since I see no way in which the words of the Fourth Amendment can be construed to apply to
eavesdropping, that closes the matter for me. In interpreting the Bill of Rights, I willingly go as
far as a liberal construction of the language takes me, but I simply cannot in good conscience
give a meaning to words which they have never before been thought to have and which they
certainly do not have in common ordinary usage. I will not distort the words of the Amendment
in order to "keep the Constitution up to date" or "to bring it into harmony with the times." It was
never meant that this Court have such power, which, in effect, would make us a continuously
functioning constitutional convention.
With this decision the Court has completed, I hope, its rewriting of the Fourth Amendment,
which started only recently when the Court began referring incessantly to the Fourth Amendment
not so much as a law against unreasonable searches and seizures as one to protect an individual's
privacy. By clever word juggling, the Court finds it plausible to argue that language aimed
specifically at searches and seizures of things that can be searched and seized may, to protect
privacy, be applied to eavesdropped evidence of conversations that can neither be searched nor
seized. Few things happen to an individual that do not affect his privacy in one way or another.
Thus, by arbitrarily substituting the Court's language, designed to protect privacy, for the

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Constitution's language, designed to protect against unreasonable searches and seizures, the
Court has made the Fourth Amendment its vehicle for holding all laws violative of the
Constitution which offend the Court's broadest concept of privacy. As I said in Griswold v.
Connecticut, :
"The Court talks about a constitutional 'right of privacy' as though there is some
constitutional provision or provisions forbidding any law ever to be passed which might
abridge the 'privacy' of individuals. But there is not." (Dissenting opinion, at .)

CALIFORNIA V. CARNEY, 471 U. S. 386 (1985)
Syllabus
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A Drug Enforcement Administration (DEA) agent, who had information that respondent's
mobile motor home was being used to exchange marihuana for sex, watched respondent
approach a youth who accompanied respondent to the motor home, which was parked in a lot in
downtown San Diego. The agent and other agents then kept the vehicle under surveillance, and
stopped the youth after he left the vehicle. He told them that he had received marihuana in return
for allowing respondent sexual contacts. At the agents' request, the youth returned to the motor
home and knocked on the door; respondent stepped out. Without a warrant or consent, one agent
then entered the motor home and observed marihuana. A subsequent search of the motor home at
the police station revealed additional marihuana, and respondent was charged with possession of
marihuana for sale. After his motion to suppress the evidence discovered in the motor home was
denied, respondent was convicted in California Superior Court on a plea of nolo contendere. The
California Court of Appeal affirmed. The California Supreme Court reversed, holding that the
search of the motor home was unreasonable and that the motor vehicle exception to the warrant
requirement of the Fourth Amendment did not apply, because expectations of privacy in a motor
home are more like those in a dwelling than in an automobile.
Held: The warrantless search of respondent's motor home did not violate the Fourth Amendment.
(a) When a vehicle is being used on the highways or is capable of such use and is found
stationary in a place not regularly used for residential purposes, the two justifications for the
vehicle exception come into play. First, the vehicle is readily mobile, and, second, there is a
reduced expectation of privacy stemming from the pervasive regulation of vehicles capable of
traveling on highways. Here, while respondent's vehicle possessed some attributes of a home, it
clearly falls within the vehicle exception. To distinguish between respondent's motor home and
an ordinary sedan for purposes of the vehicle exception would require that the exception be
applied depending on the size of the vehicle and the quality of its appointments. Moreover, to fail
to apply the exception to vehicles such as a motor home would ignore the fact that a motor home
lends itself easily to use as an instrument of illicit drug traffic or other illegal activity. Pp. -394.
(b) The search in question was not unreasonable. It was one that a magistrate could have
authorized if presented with the facts. The DEA agents, based on uncontradicted evidence that
respondent was distributing a controlled substance from the vehicle, had abundant probable
cause to enter and search the vehicle.
CHIEF JUSTICE BURGER delivered the opinion of the Court.
We granted certiorari to decide whether law enforcement agents violated the Fourth Amendment
when they conducted a warrantless search, based on probable cause, of a fully mobile "motor
home" located in a public place.

Updated 3/9/12
I
On May 31, 1979, Drug Enforcement Agency Agent Robert Williams watched respondent, a
youth in downtown San Diego. The youth accompanied Carney to a Dodge Mini Motor Home
parked in a nearby lot. Carney and the youth closed the window shades in the motor home,
including one across the front window. Agent Williams had previously received uncorroborated
information that the same motor home was used by another person who was exchanging
marihuana for sex. Williams, with assistance from other agents, kept the motor home under
surveillance for the entire one and one-quarter hours that Carney and the youth remained inside.
When the youth left the motor home, the agents followed and stopped him. The youth told the
agents that he had received marihuana in return for allowing Carney sexual contacts.
At the agents' request, the youth returned to the motor home and knocked on its door; Carney
stepped out. The agents identified themselves as law enforcement officers. Without a warrant or
consent, one agent entered the motor home and observed marihuana, plastic bags, and a scale of
the kind used in weighing drugs on a table. Agent Williams took Carney into custody and took
possession of the motor home. A subsequent search of the motor home at the police station
revealed additional marihuana in the cupboards and refrigerator.
Respondent was charged with possession of marihuana for sale. At a preliminary hearing, he
moved to suppress the evidence discovered in the motor home. The Magistrate denied the
motion, upholding the initial search as a justifiable search for other persons, and the subsequent
search as a routine inventory search.
Respondent renewed his suppression motion in the Superior Court. The Superior Court also
rejected the claim, holding that there was probable cause to arrest respondent, that the search of
the motor home was authorized under the automobile exception to the Fourth Amendment's
warrant requirement, and that the motor home itself could be seized without a warrant as an
instrumentality of the crime. Respondent then pleaded nolo contendere to the charges against
him, and was placed on probation for three years.
Respondent appealed from the order placing him on probation. The California Court of Appeal
affirmed, reasoning that the vehicle exception applied to respondent's motor home.
The California Supreme Court reversed the conviction. The Supreme Court did not disagree with
the conclusion of the trial court that the agents had probable cause to arrest respondent and to
believe that the vehicle contained evidence of a crime; however, the court held that the search
was unreasonable because no warrant was obtained, rejecting the State's argument that the
vehicle exception to the warrant requirement should apply. That court reached its decision by
concluding that the mobility of a vehicle "is no longer the prime justification for the automobile
exception; rather, the answer lies in the diminished expectation of privacy which surrounds the
automobile.'" The California Supreme Court held that the expectations of privacy in a motor
home are more like those in a dwelling than in an automobile because the primary function of
motor homes is not to provide transportation but to "provide the occupant with living quarters."
We granted certiorari, 465 U.S. 1098 (1984). We reverse.

Updated 3/9/12
II
The Fourth Amendment protects the "right of the people to be secure in their persons, houses,
papers, and effects, against unreasonable searches and seizures." This fundamental right is
preserved by a requirement that searches be conducted pursuant to a warrant issued by an
independent judicial officer. There are, of course, exceptions to the general rule that a warrant
must be secured before a search is undertaken; one is the so-called "automobile exception" at
issue in this case. This exception to the warrant requirement was first set forth by the Court 60
years ago in Carroll v. United States, (1925). There, the Court recognized that the privacy
interests in an automobile are constitutionally protected; however, it held that the ready mobility
of the automobile justifies a lesser degree of protection of those interests. The Court rested this
exception on a long-recognized distinction between stationary structures and vehicles:
"The guaranty of freedom from unreasonable searches and seizures by the Fourth
Amendment has been construed, practically since the beginning of Government, as
recognizing a necessary difference between a search of a store, dwelling house or other
structure in respect of which a proper official warrant readily may be obtained, and a
search of a ship, motor boat, wagon or automobile, for contraband goods, where it is not
practicable to secure a warrant because the vehicle can be quickly moved out of the
locality or jurisdiction in which the warrant must be sought."
Id. at (emphasis added).
The capacity to be "quickly moved" was clearly the basis of the holding in Carroll, and our cases
have consistently recognized ready mobility as one of the principal bases of the automobile
exception. See Chambers v. Maroney , (1970); In Chambers, for example, commenting on the
rationale for the vehicle exception, we noted that "the opportunity to search is fleeting since a car
is readily movable."
…
However, although ready mobility alone was perhaps the original justification for the vehicle
exception, our later cases have made clear that ready mobility is not the only basis for the
exception. The reasons for the vehicle exception, we have said, are twofold.
"Besides the element of mobility, less rigorous warrant requirements govern because the
expectation of privacy with respect to one's automobile is significantly less than that relating to
one's home or office."
Ibid.
Even in cases where an automobile was not immediately mobile, the lesser expectation of
privacy resulting from its use as a readily mobile vehicle justified application of the vehicular
exception. See, e.g., Cady v. Dombrowski, supra. In some cases, the configuration of the vehicle
contributed to the lower expectations of privacy; for example, we held in Cardwell v. Lewis,
supra, that, because the passenger compartment of a standard automobile is relatively open to
plain view, there are lesser expectations of privacy. But even when enclosed "repository" areas
have been involved, we have concluded that the lesser expectations of privacy warrant

Updated 3/9/12
application of the exception. We have applied the exception in the context of a locked car trunk,
Cady v. Dombrowski, supra, a sealed package in a car trunk, Ross, supra, a closed compartment
under the dashboard, Chambers v. Maroney, supra, the interior of a vehicle's upholstery, Carroll,
supra, or sealed packages inside a covered pickup truck, United States v. Johns, (1985).
These reduced expectations of privacy derive not from the fact that the area to be searched is in
plain view, but from the pervasive regulation of vehicles capable of traveling on the public
highways. Cady v. Dombrowsk, supra, at -441. As we explained in South Dakota v.
Opperman, an inventory search case:
"Automobiles, unlike homes, are subjected to pervasive and continuing governmental regulation
and controls, including periodic inspection and licensing requirements. As an everyday
occurrence, police stop and examine vehicles when license plates or inspection stickers have
expired, or if other violations, such as exhaust fumes or excessive noise, are noted, or if
headlights or other safety equipment are not in proper working order." 428 U.S. at .
The public is fully aware that it is accorded less privacy in its automobiles because of this
compelling governmental need for regulation. Historically,
"individuals always have been on notice that movable vessels may be stopped and searched on
facts giving rise to probable cause that the vehicle contains contraband, without the protection
afforded by a magistrate's prior evaluation of those facts." Ross, supra, at , n. 8.
In short, the pervasive schemes of regulation, which necessarily lead to reduced expectations of
privacy, and the exigencies attendant to ready mobility justify searches without prior recourse to
the authority of a magistrate so long as the overriding standard of probable cause is met.
When a vehicle is being used on the highways, or if it is readily capable of such use and is found
stationary in a place not regularly used for residential purposes -- temporary or otherwise -- the
two justifications for the vehicle exception come into play. First, the vehicle is obviously readily
mobile by the turn of an ignition key, if not actually moving. Second, there is a reduced
expectation of privacy stemming from its use as a licensed motor vehicle subject to a range of
police regulation inapplicable to a fixed dwelling. At least in these circumstances, the overriding
societal interests in effective law enforcement justify an immediate search before the vehicle and
its occupants become unavailable.
…
Respondent urges us to distinguish his vehicle from other vehicles within the exception because
it was capable of functioning as a home. In our increasingly mobile society, many vehicles used
for transportation can be and are being used not only for transportation but for shelter, i.e., as a
"home" or "residence." To distinguish between respondent's motor home and an ordinary sedan
for purposes of the vehicle exception would require that we apply the exception depending upon
the size of the vehicle and the quality of its appointments. Moreover, to fail to apply the
exception to vehicles such as a motor home ignores the fact that a motor home lends itself easily
to use as an instrument of illicit drug traffic and other illegal activity. In United States v.
Ross, 456 U.S. at , we declined to distinguish between "worthy" and "unworthy" containers,

Updated 3/9/12
noting that "the central purpose of the Fourth Amendment forecloses such a distinction." We
decline today to distinguish between "worthy" and "unworthy" vehicles which are either on the
public roads and highways, or situated such that it is reasonable to conclude that the vehicle is
not being used as a residence.
…
III
The question remains whether, apart from the lack of a warrant, this search was unreasonable.
Under the vehicle exception to the warrant requirement, "only the prior approval of the
magistrate is waived; the search otherwise must be such as the magistrate could authorize." Ross,
supra, at .
This search was not unreasonable; it was plainly one that the magistrate could authorize if
presented with these facts. The DEA agents had fresh, direct, uncontradicted evidence that the
respondent was distributing a controlled substance from the vehicle, apart from evidence of other
possible offenses. The agents thus had abundant probable cause to enter and search the vehicle
for evidence of a crime notwithstanding its possible use as a dwelling place.
The judgment of the California Supreme Court is reversed, and the case is remanded for further
proceedings not inconsistent with this opinion.
It is so ordered.

CALIFORNIA V. GREENWOOD 468 U.S. 35 (1988)
Syllabus
Updated 3/9/12
Acting on information indicating that respondent Greenwood might be engaged in narcotics
trafficking, police twice obtained from his regular trash collector garbage bags left on the curb in
front of his house. On the basis of items in the bags which were indicative of narcotics use, the
police obtained warrants to search the house, discovered controlled substances during the
searches, and arrested respondents on felony narcotics charges. Finding that probable cause to
search the house would not have existed without the evidence obtained from the trash searches,
the State Superior Court dismissed the charges under People v. Krivda, which held that
warrantless trash searches violate the Fourth Amendment and the California Constitution.
Although noting a post-Krivda state constitutional amendment eliminating the exclusionary rule
for evidence seized in violation of state, but not federal, law, the State Court of Appeal affirmed
on the ground that Krivda was based on federal, as well as state, law.
Held:
1. The Fourth Amendment does not prohibit the warrantless search and seizure of garbage left
for collection outside the curtilage of a home.
…
(a) Since respondents voluntarily left their trash for collection in an area particularly
suited for public inspection, their claimed expectation of privacy in the inculpatory items
they discarded was not objectively reasonable. It is common knowledge that plastic
garbage bags left along a public street are readily accessible to animals, children,
scavengers, snoops, and other members of the public. Moreover, respondents placed their
refuse at the curb for the express purpose of conveying it to a third party, the trash
collector, who might himself have sorted through it or permitted others, such as the
police, to do so. The police cannot reasonably be expected to avert their eyes from
evidence of criminal activity that could have been observed by any member of the public.
(b) Greenwood's alternative argument that his expectation of privacy in his garbage
should be deemed reasonable as a matter of federal constitutional law because the
warrantless search and which he contends survived the state constitutional amendment, is
without merit. The reasonableness of a search for Fourth Amendment purposes does not
depend upon privacy concepts embodied in the law of the particular State in which the
search occurred; rather, it turns upon the understanding of society as a whole that certain
areas deserve the most scrupulous protection from government invasion. There is no such
understanding with respect to garbage left for collection at the side of a public street.
JUSTICE WHITE delivered the opinion of the Court.
The issue here is whether the Fourth Amendment prohibits the warrantless search and seizure of
garbage left for collection outside the curtilage of a home. We conclude, in accordance with the
vast majority of lower courts that have addressed the issue, that it does not.

Updated 3/9/12
I
In early 1984, Investigator Jenny Stracner of the Laguna Beach Police Department received
information indicating that respondent Greenwood might be engaged in narcotics trafficking.
Stracner learned that a criminal suspect had informed a federal drug enforcement agent in
February, 1984, that a truck filled with illegal drugs was en route to the Laguna Beach address at
which Greenwood resided. In addition, a neighbor complained of heavy vehicular traffic late at
night in front of Greenwood's single-family home. The neighbor reported that the vehicles
remained at Greenwood's house for only a few minutes.
Stracner sought to investigate this information by conducting a surveillance of Greenwood's
home. She observed several vehicles make brief stops at the house during the late-night and
early-morning hours, and she followed a truck from the house to a residence that had previously
been under investigation as a narcotics trafficking location.
On April 6, 1984, Stracner asked the neighborhood's regular trash collector to pick up the plastic
garbage bags that Greenwood had left on the curb in front of his house and to turn the bags over
to her without mixing their contents with garbage from other houses. The trash collector cleaned
his truck bin of other refuse, collected the garbage bags from the street in front of Greenwood's
house, and turned the bags over to Stracner. The officer searched through the rubbish
and found items indicative of narcotics use. She recited the information that she had gleaned
from the trash search in an affidavit in support of a warrant to search Greenwood's home.
Police officers encountered both respondents at the house later that day when they arrived to
execute the warrant. The police discovered quantities of cocaine and hashish during their search
of the house. Respondents were arrested on felony narcotics charges. They subsequently posted
bail.
The police continued to receive reports of many late-night visitors to the Greenwood house. On
May 4, Investigator Robert Rahaeuser obtained Greenwood's garbage from the regular trash
collector in the same manner as had Stracner. The garbage again contained evidence of narcotics
use.
Rahaeuser secured another search warrant for Greenwood's home based on the information from
the second trash search. The police found more narcotics and evidence of narcotics trafficking
when they executed the warrant. Greenwood was again arrested.
The Superior Court dismissed the charges against respondents on the authority of People v.
Krivda, which held that warrantless trash searches violate the Fourth Amendment and the
California Constitution. The court found that the police would not have had probable cause to
search the Greenwood home without the evidence obtained from the trash searches.
The Court of Appeal affirmed. The court noted at the outset that the fruits of warrantless trash
searches could no longer be suppressed if Krivda were based only on the California Constitution,
because, since 1982, the State has barred the suppression of evidence seized in violation of
California law but not federal law. But Krivda, a decision binding on the Court of Appeal, also

Updated 3/9/12
held that the fruits of warrantless trash searches were to be excluded under federal law. Hence,
the Superior Court was correct in dismissing the charges against respondents.
The California Supreme Court denied the State's petition for review of the Court of Appeal's
decision. We granted certiorari, 483 U.S. 1019, and now reverse.
II
The warrantless search and seizure of the garbage bags left at the curb outside the Greenwood
house would violate the Fourth Amendment only if respondents manifested a subjective
expectation of privacy in their garbage that society accepts as objectively reasonable.
Respondents do not disagree with this standard.
They assert, however, that they had, and exhibited, an expectation of privacy with respect to the
trash that was searched by the police: the trash, which was placed on the street for collection at a
fixed time, was contained in opaque plastic bags, which the garbage collector was expected to
pick up, mingle with the trash of others, and deposit at the garbage dump. The trash was only
temporarily on the street, and there was little likelihood that it would be inspected by anyone.
It may well be that respondents did not expect that the contents of their garbage bags would
become known to the police or other members of the public. An expectation of privacy does not
give rise to Fourth Amendment protection,
However, unless society is prepared to accept that expectation as objectively reasonable.
Here, we conclude that respondents exposed their garbage to the public sufficiently to defeat
their claim to Fourth Amendment protection. It is common knowledge that plastic garbage bags
left on or at the side of a public street are readily accessible to animals, children, scavengers,
snoops, and other members of the public. Moreover, respondents placed their refuse at the curb
for the express purpose of conveying it to a third party, the trash collector, who might himself
have sorted through respondents' trash or permitted others, such as the police, to do so.
Accordingly, having deposited their garbage "in an area particularly suited for public inspection
and, in a manner of speaking, public consumption, for the express purpose of having strangers
take it," United States v. Reicherter (1978), respondents could have had no reasonable
expectation of privacy in the inculpatory items that they discarded.
Furthermore, as we have held, the police cannot reasonably be expected to avert their eyes from
evidence of criminal activity that could have been observed by any member of the public. Hence,
"what a person knowingly exposes to the public, even in his own home or office, is not a subject
of Fourth Amendment protection." Katz v. United States, supra, at . We held in Smith v.
Maryland, (1979), for example, that the police did not violate the Fourth Amendment by causing
a pen register to be installed at the telephone company's offices to record the telephone numbers
dialed by a criminal suspect. An individual has no legitimate expectation of privacy in the
numbers dialed on his telephone, we reasoned, because he voluntarily conveys those numbers to
the telephone company when he uses the telephone. Again, we observed that "a person has no
legitimate expectation of privacy in information he voluntarily turns over to third parties."
Similarly, we held in California v. Ciraolo, supra, that the police were not required by the Fourth
Amendment to obtain a warrant before conducting surveillance of the respondent's fenced

Updated 3/9/12
backyard from a private plane flying at an altitude of 1,000 feet. We concluded that the
respondent's expectation that his yard was protected from such surveillance was unreasonable,
because "any member of the public flying in this airspace who glanced down could have seen
everything that these officers observed." Id.at -214.
…
The Court of Appeal also held that respondent Van Houten had standing to seek the suppression
of evidence discovered during the April 4 search of Greenwood's home.
For example, State v. Ronngren, (1985), involved the search of a garbage bag that a dog, acting
"at the behest of no one," id. at 228, had dragged from the defendants' yard into the yard of a
neighbor. The neighbor deposited the bag in his own trash can, which he later permitted the
police to search. The North Dakota Supreme Court held that the search of the garbage bag did
not violate the defendants' Fourth Amendment rights.
It is not only the homeless of the Nation's cities who make use of others' refuse. For example, a
nationally syndicated consumer columnist has suggested that apartment dwellers obtain cents-off
coupons by "making friends with the fellow who handles the trash" in their buildings, and has
recounted the tale of "the 'Rich lady' from Westmont who, once a week, puts on rubber gloves
and hip boots and wades into the town garbage dump looking for labels and other proofs of
purchase" needed to obtain manufacturers' refunds.
Even the refuse of prominent Americans has not been invulnerable. In 1975, for example, a
reporter for a weekly tabloid seized five bags of garbage from the sidewalk outside the home of
Secretary of State Henry Kissinger. A newspaper editorial criticizing this journalistic "trashpicking"
observed that "evidently . . . everybody does it.'" We of course do not, as the dissent
implies, "base our conclusion" that individuals have no reasonable expectation of privacy in their
garbage on this "sole incident."
Given that the dissenters are among the tiny minority of judges whose views are contrary to ours,
we are distinctly unimpressed with the dissent's prediction that "society will be shocked to learn"
of today's decision. Post at .

UNITED STATES v. KNOTTS 460 US 276 (1983)
Syllabus
Updated 3/9/12
Having reason to believe that one Armstrong was purchasing chloroform to be used in the
manufacture of illicit drugs, Minnesota law enforcement officers arranged with the seller to place
a beeper (a radio transmitter) inside a chloroform container that was sold to Armstrong. Officers
then followed the car in which the chloroform was placed, maintaining contact by using both
visual surveillance and a monitor which received the beeper signals, and ultimately tracing the
chloroform, by beeper monitoring alone, to respondent's secluded cabin in Wisconsin. Following
three days of intermittent visual surveillance of the cabin, officers secured a search warrant and
discovered the chloroform container, and a drug laboratory in the cabin, including chemicals and
formulas for producing amphetamine. After his motion to suppress evidence based on the
warrantless monitoring of the beeper was denied, respondent was convicted in Federal District
Court for conspiring to manufacture controlled substances in violation of 21 U.S.C. 846. The
Court of Appeals reversed, holding that the monitoring of the beeper was prohibited by the
Fourth Amendment.
Held:
1) Monitoring the beeper signals did not invade any legitimate expectation of privacy on
respondent's part, and thus there was neither a "search" nor a "seizure" within the contemplation
of the Fourth Amendment. The beeper surveillance amounted principally to following an
automobile on public streets and highways. A person traveling in an automobile on public
thoroughfares has no reasonable expectation of privacy in his movements. While respondent had
the traditional expectation of privacy within a dwelling place insofar as his cabin was concerned,
such expectation of privacy would not have extended to the visual observation from public
places of the automobile arriving on his premises after leaving a public highway, or to
movements of objects such as the chloroform container outside the cabin. The fact that the
officers relied not only on visual surveillance, but also on the use of the beeper, does not alter the
situation. Nothing in the Fourth Amendment prohibited the police from augmenting their sensory
faculties with such enhancement as science and technology afforded them in this case. There is
no indication that the beeper was used in any way to reveal information as to the movement of
the chloroform container within the cabin, or in any way that would not have been visible to the
naked eye from outside the cabin.
JUSTICE REHNQUIST delivered the opinion of the Court.
A beeper is a radio transmitter, usually battery operated, which emits periodic signals that can be
picked up by a radio receiver. In this case, a beeper was placed in a five-gallon drum containing
chloroform purchased by one of respondent's codefendants. By monitoring the progress of a car
carrying the chloroform Minnesota law enforcement agents were able to trace the can of
chloroform from its place of purchase in Minneapolis, Minn., to respondent's secluded cabin near

Shell Lake, Wis. The issue presented by the case is whether such use of a beeper violated
respondent's rights secured by the Fourth Amendment to the United States Constitution.
…
I
Updated 3/9/12
After his motion to suppress evidence based on the warrantless monitoring of the beeper was
denied, respondent was convicted for conspiring to manufacture controlled substances in
violation of 21 U.S.C. 846. He was sentenced to five years' imprisonment. A divided panel of the
United States Court of Appeals for the Eighth Circuit reversed the conviction, finding that the
monitoring of the beeper was prohibited by the Fourth Amendment because its use had violated
respondent's reasonable expectation of privacy, and that all information derived after the location
of the cabin was a fruit of the illegal beeper monitoring. We granted certiorari, (1982), and we
now reverse the judgment of the Court of Appeals.
II
In Olmstead v. United States, (1928), this Court held that the wiretapping of a defendant's
private telephone line did not violate the Fourth Amendment because the wiretapping had been
effectuated without a physical trespass by the Government. Justice Brandeis, joined by Justice
Stone, dissented from that decision, believing that the actions of the Government in that case
constituted an "unjustifiable intrusion . . . upon the privacy of the individual," and therefore a
violation of the Fourth Amendment. Nearly 40 years later, in Katz v. United States, (1967), the
Court overruled Olmstead saying that the Fourth Amendment's reach " cannot turn upon the
presence or absence of a physical intrusion into any given enclosure." The Court said:
"The Government's activities in electronically listening to and recording the petitioner's
words violated the privacy upon which he justifiably relied while using the telephone
booth and thus constituted a `search and seizure' within the meaning of the Fourth
Amendment. The fact that the electronic device employed to achieve that end did not
happen to penetrate the wall of the booth can have no constitutional significance." Ibid.
In Smith v. Maryland, (1979), we elaborated on the principles stated in Katz:
"Consistently with Katz, this Court uniformly has held that the application of the Fourth
Amendment depends on whether the person invoking its protection can claim a
`justifiable,' a `reasonable,' or a `legitimate expectation of privacy' that has been invaded
by government action.” Citations omitted.
This inquiry, as Mr. Justice Harlan aptly noted in his Katz concurrence, normally two discrete
questions. The first is whether the individual, by his conduct, has `exhibited an actual
(subjective) expectation of privacy,' - whether, in the words of the Katz majority, the individual
has shown that `he seeks to preserve something as private.' The second question is whether the
individual's subjective expectation of privacy is `one that society is prepared to recognize as

"reasonable,"' id., at 361 - whether, in the words of the Katz majority, the individual's
expectation, viewed objectively, is `justifiable' under the circumstances.
Updated 3/9/12
The governmental surveillance conducted by means of the beeper in this case amounted
principally to the following of an automobile on public streets and highways. We have
commented more than once on the diminished expectation of privacy in an automobile:
"One has a lesser expectation of privacy in a motor vehicle because its function is transportation
and it seldom serves as one's residence or as the repository of personal effects. A car has little
capacity for escaping public scrutiny. It travels public thoroughfares where both its occupants
and its contents are in plain view." Cardwell v. Lewis, (1974).
A person traveling in an automobile on public thoroughfares has no reasonable expectation of
privacy in his movements from one place to another. When Petschen traveled over the public
streets he voluntarily conveyed to anyone who wanted to look the fact that he was traveling over
particular roads in a particular direction, the fact of whatever stops he made, and the fact of his
final destination when he exited from public roads onto private property.
Respondent Knotts, as the owner of the cabin and surrounding premises to which Petschen
drove, undoubtedly had the traditional expectation of privacy within a dwelling place insofar as
the cabin was concerned:
"Crime, even in the privacy of one's own quarters, is, of course, of grave concern to
society, and the law allows such crime to be reached on proper showing. The right of
officers to thrust themselves into a home is also of grave concern, not only to the
individual, but to a society which chooses to dwell in reasonable security and freedom
from surveillance. When the right of privacy must reasonably yield to the right of search
is, as a rule, to be decided by a judicial officer, not by a policeman or government
enforcement agent." Johnson v. United States, (1948)
But no such expectation of privacy extended to the visual observation of Petschen's automobile
arriving on his premises after leaving a public highway, nor to movements of objects such as the
drum of chloroform outside the cabin in the "open fields." Hester v. United States, (1924).
Visual surveillance from public places along Petschen's route or adjoining Knotts' premises
would have sufficed to reveal all of these facts to the police. The fact that the officers in this case
relied not only on visual surveillance, but also on the use of the beeper to signal the presence of
Petschen's automobile to the police receiver, does not alter the situation. Nothing in the Fourth
Amendment prohibited the police from augmenting the sensory faculties bestowed upon them at
birth with such enhancement as science and technology afforded them in this case. In United
States v. Lee, (1927), the Court said:
"But no search on the high seas is shown. The testimony of the boatswain shows that he
used a searchlight. It is not shown that there was any exploration below decks or under
hatches. For aught that appears, the cases of liquor were on deck and, like the defendants,

were discovered before the motor boat was boarded. Such use of a searchlight is
comparable to the use of a marine glass or a field glass. It is not prohibited by the
Constitution." Id., at 563.
Updated 3/9/12
We have recently had occasion to deal with another claim which was to some extent a factual
counterpart of respondent's assertions here. In Smith v. Maryland, we said:
"This analysis dictates that Smith can claim no legitimate expectation of privacy here.
When he used his phone, Smith voluntarily conveyed numerical information to the
telephone company and `exposed' that information to its equipment in the ordinary course
of business. In so doing, Smith assumed the risk that the company would reveal to police
the numbers he dialed. The switching equipment that processed those numbers is merely
the modern counterpart of the operator who, in an earlier day, personally completed calls
for the subscriber. Smith concedes that if he had placed his calls through an operator, he
could claim no legitimate expectation of privacy. Citation omitted. We are not inclined to
hold that a different constitutional result is required because the telephone company has
decided to automate." -745.
Respondent does not actually quarrel with this analysis, though he expresses the generalized
view that the result of the holding sought by the Government would be that "twenty-four hour
surveillance of any citizen of this country will be possible, without judicial knowledge or
supervision." But the fact is that the "reality hardly suggests abuse," Zurcher v. Stanford (1978);
if such dragnet-type law enforcement practices as respondent envisions should eventually occur,
there will be time enough then to determine whether different constitutional principles may be
applicable. Insofar as respondent's complaint appears to be simply that scientific devices such as
the beeper enabled the police to be more effective in detecting crime, it simply has no
constitutional foundation. We have never equated police efficiency with unconstitutionality, and
we decline to do so now.
Respondent specifically attacks the use of the beeper insofar as it was used to determine that the
can of chloroform had come to rest on his property at Shell Lake, Wis. He repeatedly challenges
the "use of the beeper to determine the location of the chemical drum at Respondent's premises,"
he states that "the government thus overlooks the fact that this case involves the sanctity of
Respondent's residence, which is accorded the greatest protection available under the Fourth
Amendment." Ibid. The Court of Appeals appears to have rested its decision on this ground:
"As noted above, a principal rationale for allowing warrantless tracking of beepers,
particularly beepers in or on an auto, is that beepers are merely a more effective means of
observing what is already public. But people pass daily from public to private spheres.
When police agents track bugged personal property without first obtaining a warrant,
they must do so at the risk that this enhanced surveillance, intrusive at best, might push
fortuitously and unreasonably into the private sphere protected by the Fourth
Amendment."

Updated 3/9/12
We think that respondent's contentions, and the above-quoted language from the opinion of the
Court of Appeals, to some extent lose sight of the limited use which the government made of the
signals from this particular beeper. As we have noted, nothing in this record indicates that the
beeper signal was received or relied upon after it had indicated that the drum containing the
chloroform had ended its automotive journey at rest on respondent's premises in rural Wisconsin.
Admittedly, because of the failure of the visual surveillance, the beeper enabled the law
enforcement officials in this case to ascertain the ultimate resting place of the chloroform when
they would not have been able to do so had they relied solely on their naked eyes. But scientific
enhancement of this sort raises no constitutional issues which visual surveillance would not also
raise. A police car following Petschen at a distance throughout his journey could have observed
him leaving the public highway and arriving at the cabin owned by respondent, with the drum of
chloroform still in the car. This fact, along with others, was used by the government in obtaining
a search warrant which led to the discovery of the clandestine drug laboratory. But there is no
indication that the beeper was used in any way to reveal information as to the movement of the
drum within the cabin, or in any way that would not have been visible to the naked eye from
outside the cabin. Just as notions of physical trespass based on the law of real property were not
dispositive in Katz v. United States, (1967), neither were they dispositive in Hester v. United
States, (1924).
We thus return to the question posed at the beginning of our inquiry in discussing Katz, supra;
did monitoring the beeper signals complained of by respondent invade any legitimate expectation
of privacy on his part? For the reasons previously stated, we hold it did not. Since it did not,
there was neither a "search" nor a "seizure" within the contemplation of the Fourth Amendment.
The judgment of the Court of Appeals is therefore
Reversed.
Concurring Opinion
JUSTICE STEVENS
Since the respondent in this case has never questioned the installation of the radio transmitter in
the chloroform drum, see ante, at 279, n., I agree that it was entirely reasonable for the police
officers to make use of the information received over the airwaves when they were trying to
ascertain the ultimate destination of the chloroform. I do not join the Court's opinion, however,
because it contains two unnecessarily broad dicta: one distorts the record in this case, and both
may prove confusing to courts that must apply this decision in the future.
…
Second, the Court suggests that the Fourth Amendment does not inhibit "the police from
augmenting the sensory faculties bestowed upon them at birth with such enhancement as science
and technology afforded them." Ibid. But the Court held to the contrary in Katz v. United
States, (1967). Although the augmentation in this case was unobjectionable, it by no means
follows that the use of electronic detection techniques does not implicate especially sensitive
concerns.

UNITED STATES v. KARO ET AL. 468 US 705 (1984)
Syllabus
Updated 3/9/12
After a Drug Enforcement Administration (DEA) agent learned that respondents Karo, Horton,
and Harley had ordered 50 gallons of ether from a Government informant, who had told the
agent that the ether was to be used to extract cocaine from clothing that had been imported into
the United States, the Government obtained a court order authorizing the installation and
monitoring of a beeper in one of the cans of ether. With the informant's consent, DEA agents
substituted their own can containing a beeper for one of the cans in the shipment. Thereafter,
agents saw Karo pick up the ether from the informant, followed Karo to his house, and
determined by using the beeper that the ether was inside the house, where it was then monitored.
The ether then moved in succession to two other houses, including Horton's, before it was moved
first to a locker in one commercial storage facility and then to a locker in another such facility.
Both lockers were rented jointly by Horton and Harley. Finally, the ether was removed from the
second storage facility by respondent Rhodes and an unidentified woman and transported in
Horton's truck, first to Rhodes' house and then to a house rented by Horton, Harley, and
respondent Steele. Using the beeper monitor, agents determined that the beeper can was inside
the house, and obtained a warrant to search the house based in part on information derived
through use of the beeper. The warrant was executed, and Horton, Harley, Steele, and respondent
Roth were arrested, and cocaine was seized. Respondents were indicted for various offenses
relating to the cocaine. The District Court granted respondents' pretrial motion to suppress the
seized evidence on the grounds that the initial warrant to install the beeper was invalid, and that
the seizure was the tainted fruit of an unauthorized installation and monitoring of the beeper. The
Government appealed, but did not challenge the invalidation of the initial warrant. The Court of
Appeals affirmed, except with respect to Rhodes, holding that a warrant was required to install
the beeper in the can of ether and to monitor it in private dwellings and storage lockers, that the
warrant for the search of the house rented by Horton, Harley, and Steele, and the resulting
seizure, were tainted by the Government's prior illegal conduct, and that therefore the evidence
was properly suppressed as to Horton, Harley, Steele, Roth, and Karo.
Held:
1. No Fourth Amendment interest of Karo or of any other respondent was infringed by the
installation of the beeper. The informant's consent was sufficient to validate the installation. And
the transfer of the beeper-laden can to Karo was neither a search nor a seizure, since it conveyed
no information that Karo wished to keep private and did not interfere with anyone's possessory
interest in a meaningful way.
2. The monitoring of a beeper in a private residence, a location not opened to visual surveillance,
violates the Fourth Amendment rights of those who have a justifiable interest in the privacy of
the residence. Here, if a DEA agent had entered the house in question without a warrant to verify
that the ether was in the house, he would have engaged in an unreasonable search within the
meaning of the Fourth Amendment. The result is the same where, without a warrant, the
Government surreptitiously uses a beeper to obtain information that it could not have obtained
from outside the curtilage of the house. There is no reason in this case to deviate from the
general rule that a search of a house should be conducted pursuant to a warrant.

Updated 3/9/12
3. The evidence seized in the house in question, however, should not have been suppressed with
respect to any of the respondents. The information that the ether was in the house, verified by use
of the beeper without a warrant, would be inadmissible against those respondents with privacy
interests in the house, and would invalidate the search warrant, if critical to establishing probable
cause. But because locating, without prior monitoring, the ether in the second storage facility
was not an illegal search (use of the beeper not identifying the specific locker in which the ether
was located and the locker being identified only by the smell of ether emanating therefrom), and
because the ether was seen being loaded into Horton's truck, which then traveled the highways, it
is evident that there was no violation of the Fourth Amendment as to anyone with or without
standing to complain about monitoring the beeper while it was located in the truck. United States
v. Knotts. Under the circumstances, the warrant affidavit, after striking the facts about
monitoring the beeper while it was in the searched house, contained sufficient untainted
information to furnish probable cause for issuance of the search warrant.
JUSTICE WHITE delivered the opinion of the Court.
In we held that the warrantless monitoring of an electronic tracking device ("beeper") inside a
container of chemicals did not violate the Fourth Amendment when it revealed no information
that could not have been obtained through visual surveillance. In this case, we are called upon to
address two questions left unresolved in Knotts: (1) whether installation of a beeper in a
container of chemicals with the consent of the original owner constitutes a search or seizure
within the meaning of the Fourth Amendment when the container is delivered to a buyer having
no knowledge of the presence of the beeper, and (2) whether monitoring of a beeper falls within
the ambit of the Fourth Amendment when it reveals information that could not have been
obtained through visual surveillance.
In August 1980 Agent Rottinger of the Drug Enforcement Administration (DEA) learned that
respondents James Karo, Richard Horton, and William Harley had ordered 50 gallons of ether
from Government informant Carl Muehlenweg of Graphic Photo Design in Albuquerque, N. M.
Muehlenweg told Rottinger that the ether was to be used to extract cocaine from clothing that
had been imported into the United States. The Government obtained a court order authorizing the
installation and monitoring of a beeper in one of the cans of ether. With Muehlenweg's consent,
agents substituted their own can containing a beeper for one of the cans in the shipment and then
had all 10 cans painted to give them a uniform appearance.
On September 20, 1980, agents saw Karo pick up the ether from Muehlenweg. They then
followed Karo to his house using visual and beeper surveillance. At one point later that day,
agents determined by using the beeper that the ether was still inside the house, but they later
determined that it had been moved undetected to Horton's house, where they located it using the
beeper. Agent Rottinger could smell the ether from the public sidewalk near Horton's residence.
Two days later, agents discovered that the ether had once again been moved, and, using the
beeper, they located it at the residence of Horton's father. The next day, the beeper was no longer
transmitting from Horton's father's house, and agents traced the beeper to a commercial storage
facility.

Updated 3/9/12
Because the beeper equipment was not sensitive enough to allow agents to learn precisely which
locker the ether was in, agents obtained a subpoena for the records of the storage company and
learned that locker 143 had been rented by Horton. Using the beeper, agents confirmed that the
ether was indeed in one of the lockers in the row containing locker 143, and using their noses
they detected the odor of ether emanating from locker 143. On October 8 agents obtained an
order authorizing installation of an entry tone alarm into the door jamb of the locker so they
would be able to tell when the door was opened. While installing the alarm, agents observed that
the cans containing ether were still inside. Agents ceased visual and beeper surveillance, relying
instead on the entry tone alarm. However, on October 16 Horton retrieved the contents from the
locker without sounding the alarm. Agents did not learn of the entry until the manager of the
storage facility notified them that Horton had been there.
Using the beeper, agents traced the beeper can to another self-storage facility three days later.
Agents detected the smell of ether coming from locker 15 and learned from the manager that
Horton and Harley had rented that locker using an alias the same day that the ether had been
removed from the first storage facility. The agents obtained an order authorizing the installation
of an entry tone alarm in locker 15, but instead of installing that alarm, they obtained consent
from the manager of the facility to install a closed-circuit video camera in a locker that had a
view of locker 15. On February 6, 1981, agents observed, by means of the video camera, Gene
Rhodes and an unidentified woman removing the cans from the locker and loading them onto the
rear bed of Horton's pickup truck. Using both visual and beeper surveillance agents tracked the
truck to Rhodes' residence where it was parked in the driveway. Agents then observed Rhodes
and a woman bringing boxes and other items from inside the house and loading the items into the
trunk of an automobile. Agents did not see any cans being transferred from the pickup.
At about 6 p. m. on February 6, the car and the pickup left the driveway and traveled along
public highways to Taos. During the trip, the two vehicles were under both physical and
electronic surveillance. When the vehicles arrived at a house in Taos rented by Horton, Harley,
and Michael Steele, the agents did not maintain tight surveillance for fear of detection. When the
vehicles left the Taos residence, agents determined, using the beeper monitor, that the beeper can
was still inside the house. Again on February 7, the beeper revealed that the ether can was still on
the premises. At one point, agents noticed that the windows of the house were wide open on a
cold windy day, leading them to suspect that the ether was being used. On February 8, the agents
applied for and obtained a warrant to search the Taos residence based in part on information
derived through use of the beeper. The warrant was executed on February 10, 1981, and Horton,
Harley, Steele, and Evan Roth were arrested, and cocaine and laboratory equipment were seized.
Respondents Karo, Horton, Harley, Steele, and Roth were indicted for conspiring to possess
cocaine with intent to distribute it and with the underlying offense. Respondent Rhodes was
indicted only for conspiracy to possess. The District Court granted respondents' pretrial motion
to suppress the evidence seized from the Taos residence on the grounds that the initial warrant to
install the beeper was invalid and that the Taos seizure was the tainted fruit of an unauthorized
installation and monitoring of that beeper. The United States appealed but did not challenge the
invalidation of the initial warrant. The Court of Appeals affirmed, except with respect to Rhodes,
holding that a warrant was required to install the beeper in one of the 10 cans of ether and to
monitor it in private dwellings and storage lockers. The warrant for the search in Taos and the

Updated 3/9/12
resulting seizure were tainted by the prior illegal conduct of the Government. The evidence was
therefore properly suppressed with respect to respondents Horton, Harley, Steele, and Roth, who
were held to have protectible interests in the privacy of the Taos dwelling, and with respect to
respondent Karo because the beeper had been installed without a warrant and had been
monitored while its ether-can host was in his house. We granted the Government's petition for
certiorari, which raised the question whether a warrant was required to authorize either the
installation of the beeper or its subsequent monitoring. We deal with each contention in turn.
Because the judgment below in favor of Karo rested in major part on the conclusion that the
installation violated his Fourth Amendment rights and that any information obtained from
monitoring the beeper was tainted by the initial illegality, we must deal with the legality of the
warrantless installation. It is clear that the actual placement of the beeper into the can violated no
one's Fourth Amendment rights. The can into which the beeper was placed belonged at the time
to the DEA, and by no stretch of the imagination could it be said that respondents then had any
legitimate expectation of privacy in it. The ether and the original 10 cans, on the other hand,
belonged to, and were in the possession of, Muehlenweg, who had given his consent to any
invasion of those items that occurred. Thus, even if there had been no substitution of cans and
the agents had placed the beeper into one of the original 10 cans, Muehlenweg's consent was
sufficient to validate the placement of the beeper in the can.
The Court of Appeals acknowledged that before Karo took control of the ether "the DEA and
Muehlenweg presumably could do with the can and ether whatever they liked without violating
Karo's rights." It did not hold that the actual placement of the beeper into the ether can violated
the Fourth Amendment. Instead, it held that the violation occurred at the time the beeper-laden
can was transferred to Karo. The court stated:
"All individuals have a legitimate expectation of privacy that objects coming into their
rightful ownership do not have electronic devices attached to them, devices that would
give law enforcement agents the opportunity to monitor the location of the objects at all
times and in every place that the objects are taken, including inside private residences and
other areas where the right to be free from warrantless governmental intrusion is
unquestioned." Ibid.
Not surprisingly, the Court of Appeals did not describe the transfer as either a "search" or a
"seizure," for plainly it is neither. A "search" occurs "when an expectation of privacy that society
is prepared to consider reasonable is infringed." The mere transfer to Karo of a can containing an
unmonitored beeper infringed no privacy interest. It conveyed no information that Karo wished
to keep private, for it conveyed no information at all. To be sure, it created a potential for an
invasion of privacy, but we have never held that potential, as opposed to actual, invasions of
privacy constitute searches for purposes of the Fourth Amendment. A holding to that effect
would mean that a policeman walking down the street carrying a parabolic microphone capable
of picking up conversations in nearby homes would be engaging in a search even if the
microphone were not turned on. It is the exploitation of technological advances that implicates
the Fourth Amendment, not their mere existence.

Updated 3/9/12
We likewise do not believe that the transfer of the container constituted a seizure. A "seizure" of
property occurs when "there is some meaningful interference with an individual's possessory
interests in that property." Ibid. Although the can may have contained an unknown and unwanted
foreign object, it cannot be said that anyone's possessory interest was interfered with in a
meaningful way. At most, there was a technical trespass on the space occupied by the beeper.
The existence of a physical trespass is only marginally relevant to the question of whether the
Fourth Amendment has been violated, however, for an actual trespass is neither necessary nor
sufficient to establish a constitutional violation. Compare (no trespass, but Fourth Amendment
violation), with (trespass, but no Fourth Amendment violation). Of course, if the presence of a
beeper in the can constituted a seizure merely because of its occupation of space, it would follow
that the presence of any object, regardless of its nature, would violate the Fourth Amendment.
We conclude that no Fourth Amendment interest of Karo or of any other respondent was
infringed by the installation of the beeper. Rather, any impairment of their privacy interests that
may have occurred was occasioned by the monitoring of the beeper.
In law enforcement officials, with the consent of the seller, installed a beeper in a 5-gallon can
of chloroform and monitored the beeper after delivery of the can to the buyer in Minneapolis,
Minn. Although there was partial visual surveillance as the automobile containing the can moved
along the public highways, the beeper enabled the officers to locate the can in the area of a cabin
near Shell Lake, Wis., and it was this information that provided the basis for the issuance of a
search warrant. As the case came to us, the installation of the beeper was not challenged; only
the monitoring was at issue. The Court held that since the movements of the automobile and the
arrival of the can containing the beeper in the area of the cabin could have been observed by the
naked eye, no Fourth Amendment violation was committed by monitoring the beeper during the
trip to the cabin. In Knotts, the record did not show that the beeper was monitored while the can
containing it was inside the cabin, and we therefore had no occasion to consider whether a
constitutional violation would have occurred had the fact been otherwise
…
This case thus presents the question whether the monitoring of a beeper in a private residence, a
location not open to visual surveillance, violates the Fourth Amendment rights of those who have
a justifiable interest in the privacy of the residence. Contrary to the submission of the United
States, we think that it does.
…
We cannot accept the Government's contention that it should be completely free from the
constraints of the Fourth Amendment to determine by means of an electronic device, without a
warrant and without probable cause or reasonable suspicion, whether a particular article — or a
person, for that matter — is in an individual's home at a particular time. Indiscriminate
monitoring of property that has been withdrawn from public view would present far too serious a
threat to privacy interests in the home to escape entirely some sort of Fourth Amendment
oversight.

Updated 3/9/12
We also reject the Government's contention that it should be able to monitor beepers in private
residences without a warrant if there is the requisite justification in the facts for believing that a
crime is being or will be committed and that monitoring the beeper wherever it goes is likely to
produce evidence of criminal activity. Warrantless searches are presumptively unreasonable,
though the Court has recognized a few limited exceptions to this general rule. See, e. g., United
States v. Ross, (automobiles); Schneckloth v. Bustamonte, (1973) (consent); Warden v. Hayden,
(1967) (exigent circumstances). The Government's contention that warrantless beeper searches
should be deemed reasonable is based upon its deprecation of the benefits and exaggeration of
the difficulties associated with procurement of a warrant. The Government argues that the
traditional justifications for the warrant requirement are inapplicable in beeper cases, but to a
large extent that argument is based upon the contention, rejected above, that the beeper
constitutes only a minuscule intrusion on protected privacy interests. The primary reason for the
warrant requirement is to interpose a "neutral and detached magistrate" between the citizen and
"the officer engaged in the often competitive enterprise of ferreting out crime." Those suspected
of drug offenses are no less entitled to that protection than those suspected of nondrug offenses.
Requiring a warrant will have the salutary effect of ensuring that use of beepers is not abused, by
imposing upon agents the requirement that they demonstrate in advance their justification for the
desired search. This is not to say that there are no exceptions to the warrant rule, because if truly
exigent circumstances exist no warrant is required under general Fourth Amendment principles.
If agents are required to obtain warrants prior to monitoring a beeper when it has been withdrawn
from public view, the Government argues, for all practical purposes they will be forced to obtain
warrants in every case in which they seek to use a beeper, because they have no way of knowing
in advance whether the beeper will be transmitting its signals from inside private premises. The
argument that a warrant requirement would oblige the Government to obtain warrants in a large
number of cases is hardly a compelling argument against the requirement. It is worthy of note
that, in any event, this is not a particularly attractive case in which to argue that it is impractical
to obtain a warrant, since a warrant was in fact obtained in this case, seemingly on probable
cause.
We are also unpersuaded by the argument that a warrant should not be required because of the
difficulty in satisfying the particularity requirement of the Fourth Amendment. The Government
contends that it would be impossible to describe the "place" to be searched, because the location
of the place is precisely what is sought to be discovered through the search. Brief for United
States 42. However true that may be, it will still be possible to describe the object into which the
beeper is to be placed, the circumstances that led agents to wish to install the beeper, and the
length of time for which beeper surveillance is requested. In our view, this information will
suffice to permit issuance of a warrant authorizing beeper installation and surveillance.
In sum, we discern no reason for deviating from the general rule that a search of a house should
be conducted pursuant to a warrant. 5
…

Dissent
Updated 3/9/12
JUSTICE STEVENS, with whom JUSTICE BRENNAN and JUSTICE MARSHALL join in
dissenting,
In my opinion the surreptitious use of a radio transmitter — whether it contains a microphone or
merely a signalling device — on an individual's personal property is both a seizure and a search
within the meaning of the Fourth Amendment. Part III of the opinion of the Court correctly
concludes that when beeper surveillance reveals the location of property that has been concealed
from public view, it constitutes a "search" within the meaning of the Fourth Amendment. I join
Part III on that understanding. However, I find it necessary to write separately because I believe
the Fourth Amendment's reach is somewhat broader than that which is explicitly acknowledged
by the Court, and in particular because my understanding of the Fourth Amendment, as well as
my understanding of the issues that have been framed for us by the parties to this case, leads me
to a different result than that reached by the Court.
The attachment of the beeper, in my judgment, constituted a "seizure.” The owner of property, of
course, has a right to exclude from it all the world, including the Government, and a concomitant
right to use it exclusively for his own purposes. When the Government attaches an electronic
monitoring device to that property, it infringes that exclusionary right; in a fundamental sense it
has converted the property to its own use. Surely such an invasion is an "interference" with
possessory rights; the right to exclude, which attached as soon as the can respondents purchased
was delivered, had been infringed. That interference is also "meaningful"; the character of the
property is profoundly different when infected with an electronic bug than when it is entirely
germ free.
The impact on possessory rights of this type of governmental conduct is illustrated by . There the
Court held that the attachment of a microphone to the heating duct of an apartment building in
order to eavesdrop on conversations in a nearby apartment implicated the Fourth Amendment:
…
Here too, by attaching a monitoring device to respondents' property, the agents usurped a part of
a citizen's property — in this case a part of respondents' exclusionary rights in their tangible
personal property. By attaching the beeper and using the container to conceal it, the Government
in the most fundamental sense was asserting "dominion and control" over the property — the
power to use the property for its own purposes. And "asserting dominion and control" is a
"seizure" in the most basic sense of the term.
The Court has developed a relatively straightforward test for determining what expectations of
privacy are protected by the Fourth Amendment with respect to the possession of personal
property. If personal property is in the plain view of the public, the possession of the property is
in no sense "private" and hence is unprotected: "What a person knowingly exposes to the public,
even in his own home or office, is not a subject of Fourth Amendment protection." When a
person's property is concealed from public view, however, then the fact of his possession is
private and the subject of Fourth Amendment protection.

Updated 3/9/12
"One point on which the Court was in virtually unanimous agreement was that a constitutional
distinction between `worthy' and `unworthy' containers would be improper. The central purpose
of the Fourth Amendment forecloses such a distinction. For just as the most frail cottage in the
kingdom is absolutely entitled to the same guarantees of privacy as the most majestic mansion,
so also may a traveler who carries a toothbrush and a few articles of clothing in a paper bag or
knotted scarf claim an equal right to conceal his possessions from official inspection as the
sophisticated executive with the locked attached case."
Thus, "the Fourth Amendment provides protection to the owner of every container that conceals
its contents from plain view." There, agents watched as a container of chloroform in which they
had placed a beeper was delivered to Knotts' codefendant and placed in his car. They then used
the beeper to track the car's movements on a single trip through a public place.
Used in this way the beeper did not disclose that the codefendant was in possession of the
property; the agents already knew that. It revealed only the route of a trip through areas open to
the public, something that was hardly concealed from public view. The Court held: "A person
traveling in an automobile on public throroughfares has no reasonable expectation of privacy in
his movements from one place to another."
It is certainly true that a homeowner has a reasonable expectation of privacy in the contents of
his home, including items owned by others. But focusing on the interest of the homeowner
should not obscure the independent interest of those in possession of property that is monitored
through the use of a beeper while the property is in a home or in any other location in which it is
concealed from public view.
In this case, the beeper enabled the agents to learn facts that were not exposed to public view.
In Knotts the agents already saw the codefendant take possession of chloroform, and therefore
the beeper accomplished no more than following the codefendant without the aid of the beeper
would have. Here, once the container went into Karo's house, the agents thereafter learned who
had the container and where it was only through use of the beeper. The beeper alone told them
when the container was taken into private residences and storage areas, and when it was
transported from one place to another.
The Court recognizes that concealment of personal property from public view gives rise to
Fourth Amendment protection when it writes: "Indiscriminate monitoring of property that has
been withdrawn from public view would present far too serious a threat to privacy interests in the
home to escape entirely some sort of Fourth Amendment oversight." This protection is not
limited to times when the beeper was in a home. The beeper also revealed when the can of ether
had been moved. When a person drives down a public thoroughfare in a car with a can of ether
concealed in the trunk, he is not exposing to public view the fact that he is in possession of a can
of ether; the can is still "withdrawn from public view" and hence its location is entitled to
constitutional protection. If a footlocker, see or even a "knotted scarf," entitles the owner of
property to conceal its location from official inspection, then surely placing it in a car suffices as
well. 9 In this case it was only the beeper that enabled the agents to discover where the can was
once it had been concealed in Karo's house. At no point thereafter did the District Court find or

Updated 3/9/12
does the Government contend that the location of the can was exposed to public view; the agents
did not know when it was moved and hence would not have been able to follow its route without
the aid of the beeper. Moreover, here the agents could not have employed visual surveillance to
determine when the can was moved for fear of detection. Because the beeper enabled them to
learn the location of personal property not exposed to public view, it invaded an interest
embraced in the Fourth Amendment's conception of a "search."
This "search" began at the moment Karo brought the can into his house and hence concealed it
from public view. As a general matter, the private citizen is entitled to assume, and in fact does
assume, that his possessions are not infected with concealed electronic devices. The concealment
of such items on personal property significantly compromises the owner's interest in privacy, by
making it impossible to conceal that item's possession and location from the Government,
despite the fact that the Fourth Amendment protects the privacy interest in the location of
personal property not exposed to public view. I find little comfort in the Court's notion that no
invasion of privacy occurs until a listener obtains some significant information by use of the
device. The expectation of privacy should be measured from the standpoint of the citizen whose
privacy is at stake, not of the Government. It is compromised the moment the invasion occurs. A
bathtub is a less private area when the plumber is present even if his back is turned.
The agents did not know who was in possession of the property or where it was once it entered
Karo's house. From that moment on it was concealed from view. Because the beeper enabled the
agents to learn the location of property otherwise concealed from public view, it infringed a
privacy interest protected by the Fourth Amendment.
The impact of beeper surveillance upon interests protected by the Fourth Amendment leads me
to what I regard as the perfectly sensible conclusion that absent exigent circumstances
Government agents have a constitutional duty to obtain a warrant before they install an electronic
device on a private citizen's property.
Because the Government does not challenge the conclusion that the warrant purporting to
authorize the installation of the beeper was obtained improperly, I would affirm the judgment of
the Court of Appeals. I would not engage in a de novo examination of the record in an effort to
determine whether there is sufficient information independent of that obtained by means of the
beeper to support the issuance of the warrant to search the Taos house. That question was not
raised in the petition for certiorari and has not been briefed by the parties. Surely this is an
inquiry that should be made in the first instance by the trial court after the parties have had an
opportunity to argue the issue.
Accordingly, I respectfully dissent.
***
"A beeper is a radio transmitter, usually battery operated, which emits periodic signals that can
be picked up by a radio receiver."

HORTON V. CALIFORNIA, 496 U. S. 128 (1990)
Syllabus
Updated 3/9/12
A California policeman determined that there was probable cause to search petitioner Horton's
home for the proceeds of a robbery and the robbers' weapons. His search warrant affidavit
referred to police reports that described both the weapons and the proceeds, but the warrant
issued by the Magistrate only authorized a search for the proceeds. Upon executing the warrant,
the officer did not find the stolen property, but did find the weapons in plain view and seized
them. The trial court refused to suppress the seized evidence, and Horton was convicted of armed
robbery. The California Court of Appeal affirmed. Since the officer had testified that, while he
was searching Horton's home for the stolen property, he was also interested in finding other
evidence connecting Horton to the robbery, the seized evidence was not discovered
"inadvertently." However, in rejecting Horton's argument that Coolidge v. New
Hampshire, therefore required suppression of that evidence, the Court of Appeal relied on a State
Supreme Court decision holding that Coolidge's discussion of the inadvertence limitation on the
"plain view" doctrine was not binding because it was contained in a four-Justice plurality
opinion.
Held:
1) The Fourth Amendment does not prohibit the warrantless seizure of evidence in plain view,
even though the discovery of the evidence was not inadvertent. Although inadvertence is a
characteristic of most legitimate plain view seizures, it is not a necessary condition.
a) Coolidge is a binding precedent. However, the second of the Coolidge plurality's two
limitations on the plain view doctrine -- that the discovery of evidence in plain view must
be inadvertent, was not essential to the Court's rejection of the State's plain view
argument in that case. Rather, the first limitation that plain view alone is never enough to
justify a warrantless seizure, adequately supports the Court's holding that gunpowder
found in vacuum sweepings from one of the automobiles seized in plain view on the
defendant's driveway in the course of his arrest could not be introduced against him
because the warrantless seizures violated the Fourth Amendment. In order for a
warrantless seizure of an object in plain view to be valid, two conditions must be satisfied
in addition to the essential predicate that the officer did not violate the Fourth
Amendment in arriving at the place from which the object could be plainly viewed. First,
the object's incriminating character must be "immediately apparent." Although the cars
in Coolidge were obviously in plain view, their probative value remained uncertain until
after their interiors were swept and examined microscopically. Second, the officer must
have a lawful right of access to the object itself. Justice Harlan, who concurred in
the Coolidge judgment but did not join the plurality's plain view discussion, may well
have rested his vote on the fact that the cars' seizure was accomplished by means of a
warrantless trespass on the defendant's property.
b) There are two flaws in the Coolidge plurality's conclusion that the inadvertence
requirement was necessary to avoid a violation of the Fourth Amendment's mandate that

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a valid warrant "particularly describe . . . the . . . things to be seized,'" . First, evenhanded
law enforcement is best achieved by applying objective standards of conduct,
rather than standards that depend upon the officer's subjective state of mind. The fact that
an officer is interested in an item and fully expects to find it should not invalidate its
seizure if the search is confined in area and duration by a warrant's terms or by a valid
exception to the warrant requirement. Second, the suggestion that the inadvertence
requirement is necessary to prevent the police from conducting general searches, or from
converting specific warrants into general warrants, is not persuasive, because that interest
is already served by the requirements that an unparticularized warrant not be issued and
that a warrantless search be circumscribed by the exigencies which justify its initiation.
Here, the search's scope was not enlarged by the warrant's omission of reference to the
weapons; indeed, no search for the weapons could have taken place if the named items
had been found or surrendered at the outset. The prohibition against general searches and
warrants is based on privacy concerns, which are not implicated when an officer with a
lawful right of access to an item in plain view seizes it without a warrant.
Justice STEVENS delivered the opinion of the Court.
In this case, we revisit an issue that was considered, but not conclusively resolved, in Coolidge v.
New Hampshire, (1971): Whether the warrantless seizure of evidence of crime in plain view is
prohibited by the Fourth Amendment if the discovery of the evidence was not inadvertent. We
conclude that even though inadvertence is a characteristic of most legitimate "plain view"
seizures, it is not a necessary condition.
I
Petitioner was convicted of the armed robbery of Erwin Wallaker, the treasurer of the San Jose
Coin Club. When Wallaker returned to his home after the Club's annual show, he entered his
garage and was accosted by two masked men, one armed with a machine gun and the other with
an electrical shocking device, sometimes referred to as a "stun gun." The two men shocked
Wallaker, bound and handcuffed him, and robbed him of jewelry and cash. During the encounter,
sufficient conversation took place to enable Wallaker subsequently to identify petitioner's
distinctive voice. His identification was partially corroborated by a witness who saw the robbers
leaving the scene, and by evidence that petitioner had attended the coin show.
Sergeant LaRault, an experienced police officer, investigated the crime and determined that there
was probable cause to search petitioner's home for the proceeds of the robber and for the
weapons used by the robbers. His affidavit for a search warrant referred to police reports that
described the weapons as well as the proceeds, but the warrant issued by the Magistrate only
authorized a search for the proceeds, including three specifically described rings.
Pursuant to the warrant, LaRault searched petitioner's residence, but he did not find the stolen
property. During the course of the search, however, he discovered the weapons in plain view and
seized them. Specifically, he seized an Uzi machine gun, a .38 caliber revolver, two stun guns, a
handcuff key, a San Jose Coin Club advertising brochure, and a few items of clothing identified
by the victim. LaRault testified that, while he was searching for the rings, he also was interested

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in finding other evidence connecting petitioner to the robbery. Thus, the seized evidence was not
discovered "inadvertently."
The trial court refused to suppress the evidence found in petitioner's home and, after a jury trial,
petitioner was found guilty and sentenced to prison. The California Court of Appeal affirmed. It
rejected petitioner's argument that our decision in Coolidge required suppression of the seized
evidence that had not been listed in the warrant because its discovery was not inadvertent. The
court relied on the California Supreme Court's decision in North v. Superior Court, (1972). In
that case, the court noted that the discussion of the inadvertence limitation on the "plain view"
doctrine in Justice Stewart's opinion in Coolidge had been joined by only three other Members of
this Court, and therefore was not binding on it. The California Supreme Court denied petitioner's
request for review. Because the California courts' interpretation of the "plain view" doctrine
conflicts with the view of other courts, and because the unresolved issue is important, we
granted certiorari, (1989).
The Fourth Amendment provides:
II
"The right of the people to be secure in their persons, houses, papers, and effects, against
unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but
upon probable cause, supported by Oath or affirmation, and particularly describing the
place to be searched, and the persons or things to be seized."
The right to security in person and property protected by the Fourth Amendment may be invaded
in quite different ways by searches and seizures. A search compromises the individual interest in
privacy; a seizure deprives the individual of dominion over his or her person or property. United
States v. Jacobsen, , (1984). The "plain view" doctrine is often considered an exception to the
general rule that warrantless searches are presumptively unreasonable, but this characterization
overlooks the important difference between searches and seizures. If an article is already in plain
view, neither its observation nor its seizure would involve any invasion of privacy. A seizure of
the article, however, would obviously invade the owner's possessory interest. If "plain view"
justifies an exception from an otherwise applicable warrant requirement, therefore, it must be an
exception that is addressed to the concerns that are implicated by seizures, rather than by
searches.
The criteria that generally guide "plain view" seizures were set forth in Coolidge v. New
Hampshire, (1971). The Court held that the seizure of two automobiles parked in plain view on
the defendant's driveway in the course of arresting the defendant violated the Fourth
Amendment. Accordingly, particles of gun powder that had been subsequently found in vacuum
sweepings from one of the cars could not be introduced in evidence against the defendant. The
State endeavored to justify the seizure of the automobiles, and their subsequent search at the
police station, on four different grounds, including the "plain view" doctrine. The scope of that
doctrine as it had developed in earlier cases was fairly summarized in these three paragraphs
from Justice Stewart's opinion:

Updated 3/9/12
"It is well established that, under certain circumstances, the police may seize evidence in
plain view without a warrant. But it is important to keep in mind that, in the vast majority
of cases, any evidence seized by the police will be in plain view, at least at the moment of
seizure. The problem with the 'plain view' doctrine has been to identify the circumstances
in which plain view has legal significance, rather than being simply the normal
concomitant of any search, legal or illegal."
"An example of the applicability of the 'plain view' doctrine is the situation in which the
police have a warrant to search a given area for specified objects, and in the course of the
search come across some other article of incriminating character. Where the initial
intrusion that brings the police within plain view of such an article is supported, not by a
warrant, but by one of the recognized exceptions to the warrant requirement, the seizure
is also legitimate. Thus the police may inadvertently come across evidence while in 'hot
pursuit' of a fleeing suspect. And an object that comes into view during a search incident
to arrest that is appropriately limited in scope under existing law may be seized without a
warrant. Finally, the 'plain view' doctrine has been applied where a police officer is not
searching for evidence against the accused, but nonetheless inadvertently comes across an
incriminating object.
"What the 'plain view' cases have in common is that the police officer in each of them
had a prior justification for an intrusion in the course of which he came inadvertently
across a piece of evidence incriminating the accused. The doctrine serves to supplement
the prior justification -- whether it be a warrant for another object, hot pursuit, search
incident to lawful arrest, or some other legitimate reason for being present unconnected
with a search directed against the accused -- and permits the warrantless seizure. Of
course, the extension of the original justification is legitimate only where it is
immediately apparent to the police that they have evidence before them; the 'plain view'
doctrine may not be used to extend a general exploratory search from one object to
another until something incriminating at last emerges."
Justice Stewart then described the two limitations on the doctrine that he found implicit in its
rationale: First, "that plain view alone is never enough to justify the warrantless seizure of
evidence," and second, "that the discovery of evidence in plain view must be inadvertent."
Justice Stewart's analysis of the "plain view" doctrine did not command a majority, and a
plurality of the Court has since made clear that the discussion is "not a binding precedent."
Justice Harlan, who concurred in the Court's judgment and in its response to the dissenting
opinions did not join the plurality's discussion of the "plain view" doctrine. The decision
nonetheless is a binding precedent. Before discussing the second limitation, which is implicated
in this case, it is therefore necessary to explain why the first adequately supports the Court's
judgment.
It is, of course, an essential predicate to any valid warrantless seizure of incriminating evidence
that the officer did not violate the Fourth Amendment in arriving at the place from which the
evidence could be plainly viewed. There are, moreover, two additional conditions that must be
satisfied to justify the warrantless seizure. First, not only must the item be in plain view, its

Updated 3/9/12
incriminating character must also be "immediately apparent." Thus, in Coolidge, the cars were
obviously in plain view, but their probative value remained uncertain until after the interiors
were swept and examined microscopically. Second, not only must the officer be lawfully located
in a place from which the object can be plainly seen, but he or she must also have a lawful right
of access to the object itself. As the Solicitor General has suggested, Justice Harlan's vote
in Coolidge may have rested on the fact that the seizure of the cars was accomplished by means
of a warrantless trespass on the defendant's property. In all events, we are satisfied that the
absence of inadvertence was not essential to the Court's rejection of the State's "plain view"
argument in Coolidge.
III
Justice Stewart concluded that the inadvertence requirement was necessary to avoid a violation
of the express constitutional requirement that a valid warrant must particularly describe the
things to be seized. He explained:
"The rationale of the exception to the warrant requirement, as just stated, is that a plainview
seizure will not turn an initially valid (and therefore limited) search into a 'general'
one, while the inconvenience of procuring a warrant to cover an inadvertent discovery is
great. But where the discovery is anticipated, where the police know in advance the
location of the evidence and intend to seize it, the situation is altogether different. The
requirement of a warrant to seize imposes no inconvenience whatever, or at least none
which is constitutionally cognizable in a legal system that regards warrantless searches as
'per se unreasonable' in the absence of 'exigent circumstances.'"
"If the initial intrusion is bottomed upon a warrant that fails to mention a particular
object, though the police know its location and intend to seize it, then there is a violation
of the express constitutional requirement of 'Warrants . . . particularly describing . . . the
things to be seized.'"
We find two flaws in this reasoning. First, even-handed law enforcement is best achieved by the
application of objective standards of conduct, rather than standards that depend upon the
subjective state of mind of the officer. The fact that an officer is interested in an item of evidence
and fully expects to find it in the course of a search should not invalidate its seizure if the search
is confined in area and duration by the terms of a warrant or a valid exception to the warrant
requirement. If the officer has knowledge approaching certainty that the item will be found, we
see no reason why he or she would deliberately omit a particular description of the item to be
seized from the application for a search warrant. Specification of the additional item could only
permit the officer to expand the scope of the search. On the other hand, if he or she has a valid
warrant to search for one item and merely a suspicion concerning the second, whether or not it
amounts to probable cause, we fail to see why that suspicion should immunize the second item
from seizure if it is found during a lawful search for the first. The hypothetical case put by
Justice WHITE in his dissenting opinion in Coolidge is instructive:
"Let us suppose officers secure a warrant to search a house for a rifle. While staying well
within the range of a rifle search, they discover two photographs of the murder victim,
both in plain sight in the bedroom. Assume also that the discovery of the one photograph

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was inadvertent, but finding the other was anticipated. The Court would permit the
seizure of only one of the photographs. But in terms of the 'minor' peril to Fourth
Amendment values, there is surely no difference between these two photographs: the
interference with possession is the same in each case and the officers' appraisal of the
photograph they expected to see is no less reliable than their judgment about the other.
And in both situations, the actual inconvenience and danger to evidence remain identical
if the officers must depart and secure a warrant." Id. at .
Second, the suggestion that the inadvertence requirement is necessary to prevent the police from
conducting general searches, or from converting specific warrants into general warrants, is not
persuasive, because that interest is already served by the requirements that no warrant issue
unless it "particularly describes the place to be searched and the persons or things to be seized."
Scrupulous adherence to these requirements serves the interests in limiting the area and duration
of the search that the inadvertence requirement inadequately protects. Once those commands
have been satisfied and the officer has a lawful right of access, however, no additional Fourth
Amendment interest is furthered by requiring that the discovery of evidence be inadvertent. If the
scope of the search exceeds that permitted by the terms of a validly issued warrant or the
character of the relevant exception from the warrant requirement, the subsequent seizure is
unconstitutional without more. Thus, in the case of a search incident to a lawful arrest,
"if the police stray outside the scope of an authorized Chimel search, they are already in
violation of the Fourth Amendment, and evidence so seized will be excluded; adding a
second reason for excluding evidence hardly seems worth the candle."
Similarly, the object of a warrantless search of an automobile also defines its scope:
"The scope of a warrantless search of an automobile thus is not defined by the nature of
the container in which the contraband is secreted. Rather, it is defined by the object of the
search and the places in which there is probable cause to believe that it may be found.
Just as probable cause to believe that a stolen lawnmower may be found in a garage will
not support a warrant to search an upstairs bedroom, probable cause to believe that
undocumented aliens are being transported in a van will not justify a warrantless search
of a suitcase. Probable cause to believe that a container placed in the trunk of a taxi
contains contraband or evidence does not justify a search of the entire cab."
In this case, the scope of the search was not enlarged in the slightest by the omission of any
reference to the weapons in the warrant. Indeed, if the three rings and other items named in the
warrant had been found at the outset -- or if petitioner had them in his possession and had
responded to the warrant by producing them immediately -- no search for weapons could have
taken place. Again, Justice WHITE's dissenting opinion in Coolidge is instructive:
"Police with a warrant for a rifle may search only places where rifles might be, and must
terminate the search once the rifle is found; the inadvertence rule will in no way reduce
the number of places into which they may lawfully look."

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As we have already suggested, by hypothesis the seizure of an object in plain view does not
involve an intrusion on privacy. If the interest in privacy has been invaded, the violation must
have occurred before the object came into plain view, and there is no need for an inadvertence
limitation on seizures to condemn it. The prohibition against general searches and general
warrants serves primarily as a protection against unjustified intrusions on privacy. But reliance
on privacy concerns that support that prohibition is misplaced when the inquiry concerns the
scope of an exception that merely authorizes an officer with a lawful right of access to an item to
seize it without a warrant.
In this case, the items seized from petitioner's home were discovered during a lawful search
authorized by a valid warrant. When they were discovered, it was immediately apparent to the
officer that they constituted incriminating evidence. He had probable cause not only to obtain a
warrant to search for the stolen property, but also to believe that the weapons and handguns had
been used in the crime he was investigating. The search was authorized by the warrant, the
seizure was authorized by the "plain view" doctrine. The judgment is affirmed.
Although the officer viewed other handguns and rifles, he did not seize them because there was
no probable cause to believe they were associated with criminal activity.
"In Coolidge, the police arrested a murder suspect in his house and thereupon seized his
automobile and searched it later at the police station, finding physical evidence that the
victim had been inside the vehicle. The record disclosed that the police had known for
some time of the probable role of the car in the crime, and there were no 'exigent
circumstances' to justify a warrantless search. Accordingly, the plurality opinion of
Justice Stewart concluded that the seizure could not be justified on the theory that the
vehicle was itself the 'instrumentality' of the crime and was discovered 'in plain view' of
the officers. Justice Stewart was of the opinion that the 'plain view' doctrine is applicable
only to the inadvertent discovery of incriminating evidence."
"If the plurality opinion in Coolidge were entitled to binding effect as precedent, we would have
difficulty distinguishing its holding from the instant case, for the discovery of petitioner's car was
no more 'inadvertent' than in Coolidge. However, that portion of Justice Stewart's plurality
opinion which proposed the adoption of new restrictions to the 'plain view' rule was signed by
only four members of the court (Stewart, J., Douglas, J., Brennan, J., and Marshall, J.).

UNITED STATES v. McCONNEY, 728 F.2d 1195, 1199 (9th Cir.) (1984)
NORRIS, Circuit Judge, delivered Parts I, II, and III of the opinion of the court.
GOODWIN, Circuit Judge, delivered Parts IV and V of the opinion of the court.
Updated 3/9/12
Winston McConney was convicted on stipulated facts of violating 18 U.S.C. § 922(h) which
prohibits a convicted felon from receiving firearms shipped in interstate commerce. His appeal
challenges the denial of his timely motion to suppress evidence as illegally obtained. We took the
case en banc for the specific purpose of resolving the issue of the appropriate standard of
appellate review for the mixed question of law and fact of "exigent circumstances."
I
On June 12, 1979, an indictment was filed in the United States District Court for the Northern
District of California accusing McConney, and thirty-one other defendants, of violating title IX
of the Organized Crime Control Act of 1970. This title, commonly known as the Racketeer
Influenced and Corrupt Organizations Act (RICO), prohibits conducting or participating in the
conduct of an enterprise through a pattern of racketeering activity. 18 U.S.C. § 1962. The
indictment identified the RICO "enterprise" as the Hell's Angels Motorcycle Club.
On the day after the indictment was filed, federal officers executed an "indicia" warrant
authorizing a search of McConney's residence and seizure of any indicia of membership in or
association with the Hell's Angels Motorcycle Club. In addition to the indicia warrant, the
searching officers possessed an arrest warrant and a Prescott warrant.
On the evening of June 13, 1979, federal agents executed the arrest and search warrants at
McConney's residence. When the agents approached the home at approximately 8:30 p.m., the
solid front door was open but an inner screen door was closed. The lead agent, Olson, knocked
on the door and announced his identity and purpose. He saw inside a person he recognized
immediately as McConney. Between McConney and the door was a second person, sitting with
his back to the door. Without waiting for a response or a refusal of entry, Olson opened the door
and led the other agents into the living room. McConney and the other person were ordered to
move several feet to a position on the floor next to a sofa in the same room. While the two men
were being handcuffed, another agent discovered a loaded pistol beneath one of the sofa
cushions. A subsequent search of the house made under the indicia warrant yielded a second
weapon.
Following the discovery of the two firearms, a count was added in a superseding indictment
charging McConney with violating 18 U.S.C. § 922(h).
After the district court denied McConney's suppression motion, the government moved to drop
the RICO charges against him and proceeded on the firearms charge. McConney saved his
objection to the denial of his motions, waived his right to a jury trial, and agreed to a court trial
on a written stipulation of facts. The court found McConney guilty as charged. The appeal from
the resulting judgment of confinement challenges the denial of the suppression motion.

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McConney contends that the entry into his home violated the federal "knock-notice" requirement
which provides that an officer, before opening a door of a house in order to enter, must give
notice of his identity and purpose and be refused admittance by the occupant. 18 U.S.C. §
3109. As this court recently stated, "section 3109 codifies a tradition embedded in Anglo-
American law and declares the reverence which the law attaches to an individual's right of
privacy in his house."
In Whitney, this court addressed the problem of officers entering a house upon announcing their
identity and purpose without first awaiting a refusal or admittance. The court recognized that
compliance with section 3109's requirements may be excused by exigent circumstances. The
government's claim here, as in Whitney, is that exigent circumstances justified the agent's failure
to await refusal of admittance.
The district court found that the agents had knocked and announced their identity, and that their
simultaneous entry (without waiting for refusal of admittance) was justified by exigent
circumstances. The district court also found that seizure of the first pistol was an incident of a
lawful arrest.
We define exigent circumstances as those circumstances that would cause a reasonable person to
believe that entry (or other relevant prompt action) was necessary to prevent physical harm to the
officers or other persons, the destruction of relevant evidence, the escape of the suspect, or some
other consequence improperly frustrating legitimate law enforcement efforts.
II
We turn first to the question of what standard of review is applicable to the district court's
determination that the federal agents' failure to comply with the requirements of section 3109
was excused by exigent circumstances. This court held that the "mixed fact-law question" of
exigent circumstances is factual in nature and therefore reviewable on appeal under the
deferential, clearly erroneous standard. We took this case en banc to decide
whether Flickinger should be overruled.
A.
In Flickinger, the panel founded its determination that the question of exigent circumstances is
subject to deferential review on two precedents it considered to be "analogous.” In Hart, we held
that the determination that government agents had done everything "reasonably necessary and
proper" to make a witness available is factual in nature and consequently subject to the clearly
erroneous test. Similarly, in Page, we held that whether consent to a search was "freely and
intelligently given" is a factual issue properly subject to clearly erroneous review. On the basis of
these cases, the Flickinger panel concluded:
Our experience dictates that the question of exigent circumstances is fundamentally the same
type of issue as the questions of voluntariness of a consent and whether officers had done
everything reasonably necessary to produce a witness. Certainly, a finding of exigent

Updated 3/9/12
circumstances is no less based on the "factfinding tribunal's experience with the mainsprings of
human conduct."
…
In Flickinger's discussion of the appropriate standard of review for the question of exigent
circumstances, we find a number of indications that our jurisprudence concerning appellate
review of mixed questions lacks clarity and coherence. First, we are struck by the difficulty the
Flickinger panel had in determining which of our standard of review precedents controlled the
case before it. This difficulty doubtless reflects the absence of clear legal guideposts in this area
of the law. Second, an even clearer indication of disarray is the conflict in our precedents
concerning the appropriate standard of review for the question of probable cause which the
Flickinger panel noted.
This disarray in standard of review jurisprudence appears to be pervasive. The Supreme Court
recently stated that "there is substantial authority in the circuits on both sides of the question of
the applicability of the rule 52(a) clearly erroneous standard to mixed questions of law and fact."
…
We begin our reexamination of Flickinger by returning to first principles of standard of review
jurisprudence in an effort to formulate an analytical framework for dealing with mixed questions.
B.
The Supreme Court has defined mixed questions as those in which "the historical facts are
admitted or established, the rule of law is undisputed, and the issue is whether the facts satisfy
the relevant statutory or constitutional standard, or to put it another way, whether the rule of law
as applied to the established facts is or is not violated." . Thus, there are three distinct steps in
deciding a mixed fact-law question. The first step is the establishment of the "basic, primary, or
historical facts: facts `in the sense of a recital of external events and the credibility of their
narrators ...'." (quoting ). The second step is the selection of the applicable rule of law. The third
step — and the most troublesome for standard of review purposes — is the application of law to
fact or, in other words, the determination "whether the rule of law as applied to the established
facts is or is not violated."
…
Yet, when we review the third of the district court's determinations — its application of law to
fact — we confront "a much-mooted issue" with "substantial authority in the circuits on both
sides of the question." We believe, however, that the well developed jurisprudence relating to
questions of pure law and pure fact offers guideposts for working our way out of this confusion.
The appropriate standard of review for a district judge's application of law to fact may be
determined, in our view, by reference to the sound principles which underlie the settled rules of
appellate review just discussed. If the concerns of judicial administration — efficiency, accuracy,
and precedential weight — make it more appropriate for a district judge to determine whether the

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established facts fall within the relevant legal definition, we should subject his determination to
deferential, clearly erroneous review. If, on the other hand, the concerns of judicial
administration favor the appellate court, we should subject the district judge's finding to de novo
review. Thus, in each case, the pivotal question is do the concerns of judicial administration
favor the district court or do they favor the appellate court.
In our view, the key to the resolution of this question is the nature of the inquiry that is required
to decide "whether the rule of law as applied to the established facts is or is not violated." If
application of the rule of law to the facts requires an inquiry that is "essentially factual," — one
that is founded "on the application of the fact-finding tribunal's experience with the mainsprings
of human conduct," — the concerns of judicial administration will favor the district court, and
the district court's determination should be classified as one of fact reviewable under the clearly
erroneous standard. If, on the other hand, the question requires us to consider legal concepts in
the mix of fact and law and to exercise judgment about the values that animate legal principles,
then the concerns of judicial administration will favor the appellate court, and the question
should be classified as one of law and reviewed de novo.
As the Supreme Court appeared to indicate in the concerns of judicial administration will
generally favor the appellate court, justifying de novo review. This is so because usually the
application of law to fact will require the consideration of legal concepts and involve the exercise
of judgment about the values underlying legal principles. In for instance, the Supreme Court
ruled that "the ultimate conclusion by the trial judge, that the defendants' conduct did not
constitute a combination or conspiracy in violation of the Sherman Act, is not to be shielded by
the `clearly erroneous test'." In explanation, the Court noted that "the question here is not one of
`fact,' but consists rather of the legal standard required to be applied to the undisputed facts of
the case." offers another instructive example. In Tex-Penn Oil, the Court treated the factual
findings of the Board of Tax Appeals as established because they were supported by substantial
evidence. In contrast, the determination by the Board that a transaction did not fall within the
non-recognition of gains provision of the Internal Revenue Code was classified as "a conclusion
of law or at least a determination of a mixed question of law and fact."
The Court thus felt that "it was to be distinguished from the findings of primary, evidentiary or
circumstantial facts ... and was subject to judicial review during which the court could substitute
its judgment for that of the board." This assessment of tax consequences did not turn on a strictly
factual inquiry. Rather, it required an analysis of the intricacies of the corporate reorganization
provisions of the Internal Revenue Code and the legislative purpose in exempting certain gains
from immediate taxation.
The predominance of factors favoring de novo review is even more striking when the mixed
question implicates constitutional rights. In cases involving such questions, the application of
law to fact will usually require that the court look to the well defined body of law concerning the
relevant constitutional provision. Thus, the Supreme Court has held that the mixed question of
probable cause is treated as a question of law and reviewed de novo. This holding implicitly
recognizes that the inquiry involved in applying the probable cause standard goes well beyond
the facts of the case and requires consideration of the abstract legal principles that inform
constitutional jurisprudence. A similar recognition, though it may be unarticulated, seems to

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underlie cases in which our court has reviewed as questions of law such mixed questions as the
reasonableness of certain restrictions on first amendment rights, ; whether there was a "search" in
an INS sweep of a factory and whether a post-deprivation hearing within forty-eight hours
following the seizure of property conformed to fourteenth amendment due process requirements.
There are, however, some types of mixed questions that are exceptions to this general
predominance of factors favoring de novo review. First, there are those mixed questions in which
the applicable legal standard provides for a strictly factual test, such as state of mind, and the
application of law to fact, consequently, involves an "essentially factual" inquiry.. In Pullman-
Standard, for example, the mixed question before the Court was whether the established facts
demonstrated the intent to discriminate required by section 703(h) of title VII of the Civil Rights
Act of 1964. Since, for the purposes of section 703(h) of title VII, intent means subjective intent,
the relevant legal standard was that of "actual motive." The Court distinguished this legal
standard from "some legal concept of discriminatory intent (emphasis added), noting that actual
motive "appears ... to be a pure question of fact." On this basis, the Court concluded that in the
case before it the concerns of judicial administration favored the district court and that the mixed
question under consideration thus "was not ... a mixed question of law and fact of the kind that in
some cases may allow an appellate court to review the facts." Id. The Court subjected the lower
court's determination to clearly erroneous review.
A trial court's determination whether established facts constitute negligence offers us a second
situation in which the concerns of judicial administration favor the district court. Because the
legal standard for judging whether conduct is negligent requires us to determine, by reference to
the "data of practical human experience," whether an individual acted "reasonably" by
community standards, the trial court's findings of fact effectively determine our legal
conclusions. Consequently, clearly erroneous review is appropriate.
Thus, because the application of law to fact will generally require the consideration of legal
principles, the concerns of judicial administration will usually favor the appellate court, and most
mixed questions will be reviewed independently. This is particularly true when the mixed
question involves constitutional rights. But we identify from existing precedent at least two
exceptions to this general rule: mixed questions in which the applicable legal standard provides
for a strictly factual test and the mixed question of negligence.
C.
In summary, to classify mixed questions of law and fact for standard of review purposes, we
adopt a functional analysis that focuses on the nature of the inquiry required when we apply the
relevant rule of law to the facts as established. The analysis is not a precise one and does not
offer any litmus test by which all mixed questions can be neatly categorized. It does not
"unerringly distinguish between findings of fact and conclusions of law." . Nonetheless, we think
that if we focus on the nature of the inquiry required in determining whether the established facts
fall within the relevant legal definition, we employ a neutral test that accurately reflects the
concerns that properly underlie standard of review jurisprudence.

Updated 3/9/12
III
Applying our functional analysis to the case at hand, we conclude that the mixed question of
exigent circumstances is reviewable de novo as a question of law, and, consequently, we
overrule Flickinger. Our reason is this: to decide if the facts satisfy the legal test of exigency —
whether, judged by an objective standard, "there was a likelihood that the occupants would
attempt to escape, resist, destroy evidence, or harm someone within," necessarily involves us in
an inquiry that goes beyond the historical facts.
The mixed question of exigency is rooted in constitutional principles and policies. Like many
such mixed questions, its resolution requires us to consider abstract legal doctrines, to weigh
underlying policy considerations, and to balance competing legal interests. In particular, its
resolution requires that we strike a balance between two sometimes conflicting societal values —
the safety of law enforcement officers and fourth amendment privacy interests. The essential and
difficult question raised by this balancing is how much risk police officers can reasonably be
expected to assume before disregarding the rules society has adopted to otherwise circumscribe
the exercise of their considerable discretionary authority in carrying out their vital law
enforcement duties.
This is a question that no amount of factfinding will answer. The inquiry requires us to ask not
merely whether the trial judge was correct in finding that Olson in fact had reason to believe, for
instance, that McConney was a member of the Hell's Angels Motorcycle Club or that he had a
prior felony conviction; it also requires a determination whether these facts and any other
information Olson had about McConney's past are sufficient to satisfy the legal standard for
exigency. We must decide, for instance, whether a reasonable belief that a suspect is a member
of the Hell's Angels Club, without demonstration of a link to criminal activity, is relevant to the
issue of exigency, cf. (membership in Hell's Angels without a link to actual criminal activity
insufficient to support a finding of probable cause to issue a search warrant). We must also
decide how much weight may be given to an officer's knowledge that a suspect has previously
been convicted of an unspecified felony.
When, as here, the application of law to fact requires us to make value judgments about the law
and its policy underpinnings, and when, as here, the application of law to fact is of clear
precedential importance, the policy reasons for de novo review are satisfied and we should not
hesitate to review the district judge's determination independently.
In conclusion, we hold that the mixed question of exigent circumstances is not reviewable under
the clearly erroneous test because it is not, like the question of intent, essentially factual. We do
not at this juncture decide how any other mixed question should be reviewed. We do, it is true,
adopt a functional analysis for the resolution of these questions. But our approach is an ad hoc
one, permitting individual analysis and classification of each type of mixed question. Under it,
we need only decide that the question of exigent circumstances is subject to de novo review.
IV
We have made the required review of the record, and we affirm the district court's holding that
exigent circumstances excused the agents' failure to await refusal of admittance before entering
McConney's home. The "knock-notice" statute provides that an officer, before opening a door of

Updated 3/9/12
a house in order to enter, must give notice of his authority and purpose, and be refused
admittance by the occupant. The requirements of section 3109 apply to locked and unlocked
doors alike. . The purpose of the requirement is twofold. First, it is to protect an individual's right
to privacy in the home to the extent possible and consistent with the execution of the warrant.
Second, it is to protect officers themselves, who might otherwise be mistaken, upon
unannounced intrusion, for someone with no right to be there. The interval of time an officer
must wait between announcement and entry depends on the circumstances of each case.
When police have properly knocked and announced their identity and purpose, mild exigency is
sufficient to justify simultaneous entry when entry can be accomplished without physical
destruction of property. Mild exigency may exist where there is a likelihood that the occupants
will try to escape, resist, or destroy evidence. More specific inferences of exigency are necessary
if entry may be obtained only by the physical destruction of property; an explicit refusal of
admittance or lapse of a significant amount of time is necessary if the officers have no facts
indicating exigency. But here the officers found an open door.
We emphasize, and McConney concedes, that the agents knocked and announced their entry.
They simultaneously opened an unlocked wire screen door through which they observed
McConney and a second then unknown person seated inside. Agent Olson had recognized
McConney as he observed him through the door, and feared for his safety and that of the other
officers if McConney were allowed time to arm himself.
Whether the circumstances present sufficient exigency necessarily involves judgment. An
unjustified but sincere fear by an officer cannot excuse noncompliance or the protection of the
occupants' privacy interest would depend on no more than an officer's anxiety. Here, however,
there is no reason to discount either the sincerity or the reasonableness of the agent's concern.
When Agent Olson served as an undercover agent, he had a close relationship with McConney.
McConney had a conviction for a violent crime, and Olson testified that he knew that McConney
was a convicted felon. Olson further knew that McConney was a drug dealer and that he was
charged with racketeering. Both types of offenses often involve the possession of firearms.
Moreover, McConney once made a statement to Olson about the "protection of members of the
club," supporting a reasonable inference that there was danger in arresting any club member.
Although any one of these factors standing alone might be insufficient to create the mild
exigency required, the combination of factors in this case satisfies the requirements of
Bustamante-Gamez. The agents did not violate section 3109.
V
McConney contends that even if the entry were unobjectionable, the first gun seized was
inadmissible as evidence because the indicia search warrant was invalid and the seizure cannot
be justified as incident to his arrest. Because we hold that the first gun was seized as an incident
to his arrest, we need not reach McConney's arguments about the indicia search warrant. Because
the same type of fourth amendment right is involved as in the determination of exigent
circumstances, we apply the same independent standard of review.

Updated 3/9/12
"Search incident to arrest" is an exception to the general rule against searches without a warrant.
The justification for permitting a warrantless search is the need to seize weapons or other things
which might be used to assault an officer or effect an escape, as well as the need to prevent the
loss or destruction of evidence. See . In legitimate search incident to arrest was limited to the
arrestee's person and the area "within his immediate control."
The critical inquiry, then, is whether the search that produced McConney's pistol was properly
limited to the area within his immediate control at the time of his arrest. The number of persons
being arrested, the number of officers present, their physical positioning with regard to the
arrestee and the place searched, the display of guns by the officers and, of course, the distance
between the arrestee and the place searched are all factors to be weighed by the court.
We conclude that the search under the sofa cushion, which revealed the loaded pistol, did not
exceed the limitations under Chimel. At the time the sofa was searched, McConney was only two
feet from the gun, and was not yet handcuffed. Chimel does not require the police to presume
that an arrestee is wholly rational. Persons under stress may attempt actions which are unlikely to
succeed. The presence of the agents with drawn guns may have limited the area McConney could
have reached had he made a sudden attempt to do so. This presence, however, was no guarantee
that armed violence could not break out when a loaded gun was only two feet away.
For the foregoing reasons, the loaded pistol was properly admitted as evidence against
McConney on the charge of violation of 18 U.S.C. § 922(h). McConney does not contend that
the evidence against him, if the pistol was properly admitted, is insufficient to support his
conviction. We need not reach the admissibility of evidence concerning the second gun as the
finding of guilt did not depend upon it.
The decision filed on March 30, 1981, and withdrawn on January 15, 1982, is superseded by this
decision.
AFFIRMED.
Dissent
NORRIS, Circuit Judge, with whom FLETCHER, Circuit Judge, joins, dissenting from the
judgment:
Although I concur fully in Parts I, II, III, and V of the court's opinion, I disagree with Part IV. I
believe that the evidentiary record before us fails to support the conclusion that exigent
circumstances justified the manner in which Agent Olson entered McConney's home and that,
accordingly, the judgment of the district court should be reversed.
I
Before proceeding to a de novo review of the trial judge's determination of exigency, we must
first review, under the clearly erroneous standard, the findings of fact on which such a
conclusion was — or could have been — based. Because the trial judge made no findings of fact
on the issue of exigency, we must as an initial matter derive those findings by drawing from the
record the reasonable inferences that are most favorable to the legal conclusion that exigency

Updated 3/9/12
existed. . It is in this process of drawing permissible inferences from the evidence and inferring
findings that I part company with the majority. The majority finds support for the trial judge's
conclusion that there was a "reasonable" basis for Olson's fear that McConney was dangerous in
four implied findings:
(1) when he was an undercover agent, Olson had had a close undercover relationship with
McConney;
(2) Olson knew that McConney was a convicted felon and that McConney had in fact
been convicted of a violent crime;
(3) Olson further knew that McConney was a drug dealer and had been charged with
racketeering; and
(4) McConney had once made a statement to Olson about protection by members of the
Hell's Angels Motorcycle Club that "supported a reasonable inference that there was
danger in arresting any club member."
While I agree that these facts would as a legal matter constitute exigency, I believe they find no
support in the evidentiary record before us. In other words, if the trial judge had explicitly made
the findings of fact the majority imputes to him, I would hold them to be clearly erroneous.
Contrary to what the majority apparently assumes, the probative evidence on the issue of
exigency is limited to an affidavit that Olson executed shortly after he arrested McConney, and
that Olson was asked to read into the record at the suppression hearing. Reporter's Transcript at
1547. The affidavit stated in relevant part:
“Prior to the execution of the warrants, I was aware that McConney was a convicted felon
and was allegedly a member of the Hell's Angels Motorcycle Club ... I recognized him
because of prior undercover law enforcement experience ... I know that members and
associates of the Hell's Angels have, in the past, been in possession of various firearms
and explosive devices and also that certain members of the club are suspected of
complicity in the attempted murder of a San Jose police officer as well as four unsolved
murders in Oregon.”
“Therefore, out of a concern for my own safety and that of the other officers, as soon as I
saw McConney, I opened the screen door....”
Reporter's Transcript at 1548, 1549, 1550.
This affidavit is the sum total of the evidence that we are permitted to consider in deciding
whether there was a reasonable basis for Olson's fear that McConney was armed and dangerous.
Although Olson also gave live testimony at the suppression hearing, none of his testimony was
linked to his state of mind at the time of his entry. Although Olson testified on direct examination
that in 1975 he had encountered McConney in undercover drug negotiations during which
McConney had promised him protection "by McConney's people" who were Hell's Angels,
Reporter's Transcript at 1551-53, he did not testify then or at any later point that he had the 1975
conversation in mind when he entered McConney's home in 1979.
…

Updated 3/9/12
Olson's affidavit thus represents the only evidence in the record on the issue of exigency. Close
scrutiny of what it says, and, more importantly, of what it does not say, makes clear that there is
no evidentiary support for the facts that the majority accepts as established.
II
In his affidavit, Olson proffered four grounds for his actions: (1) he knew that McConney was a
convicted felon; (2) McConney was "allegedly" a member of the Hell's Angels Motorcycle Club;
(3) he recognized McConney because of prior undercover law enforcement experience; and (4)
he was aware that members and associates of the Hell's Angels owned weapons and were
suspected of complicity in murders in San Jose and Oregon. A discrete analysis of each of these
grounds is instructive.
(1) Olson Knew That McConney Was a Convicted Felon. The majority states that "McConney
had a conviction for violent crime, and Olson testified that he knew that McConney was a
convicted felon." What the majority glosses over is that Olson fails to specify in his affidavit the
nature of the felony; thus there is no evidence that Olson knew or even believed that McConney
had been convicted of a crime of violence. The fact that we know independently from the record
that McConney had been convicted of armed robbery, resisting arrest, and battery does not
provide support for an inference that Olson knew that McConney had been convicted of a violent
crime. If Olson had known that fact about McConney, he could easily have so stated in his
affidavit or could have supplemented his affidavit with testimony to that effect at the suppression
hearing: in fact, the only evidence on the point is Olson's statement in his affidavit that he "was
aware that McConney was a convicted felon."
…
(2) The Hell's Angels Connection. The affidavit fails to say that Olson had any personal
knowledge that McConney was a member of the Hell's Angels Motorcycle Club or was even
associated with known members. It recites only that Olson knew that McConney "allegedly" was
a member. Absent any indication of the source of that allegation — a rumor, a tip from an
informer of known or unknown reliability, a police report, or an indictment — we cannot on the
record before us fairly evaluate this "fact" in determining whether there was an objective basis
for Olson's asserted belief that McConney was dangerous. The government suggests that the
allegation in the underlying RICO indictment that McConney was a Hell's Angel supported a
belief by Olson that he was associated with the group.
…
(3) Olson Recognized McConney From Prior Undercover Law Enforcement
Experience.Although the affidavit recites that Olson recognized McConney from past
undercover law enforcement experience, it gives no details about the encounter. The majority's
statement that Olson "had a close relationship" with McConney while serving as an undercover
agent, is sheer conjecture. The bald fact that Olson recognized McConney from past undercover
experience, without more, adds nothing to the record on the issue of exigency.
(4) Olson Knew That Some Members of the Hell's Angels Carried Arms and Were Suspected of
Complicity In Murder. Finally, the affidavit fails to suggest that McConney was associated in

Updated 3/9/12
any way — other than "alleged" common membership in the Hell's Angels organization — with
any of the unidentified members and associates of the Hell's Angels whom Olson stated he knew
had carried arms or were suspected of complicity in murders in San Jose and Oregon. In fact, the
affidavit carefully refers to such unnamed persons only as "members and associates of the Hell's
Angels" generally, not as associates of McConney personally. Even were we to assume that
McConney was still a member when he was arrested, nothing in the record suggests that it was
reasonable for Olson to believe that the violent propensities of some unidentified Hell's Angels
were shared by McConney.
…
III
When I consider the inferences that can permissibly be drawn under the most charitable view of
the evidence, I fail to see how the legal standard of exigency, or even the legal standard of "mild
exigency," cert. denied, can be satisfied without draining the concept of all legal substance and
reading the refusal of admittance requirement out of the statute altogether. That Olson believed
McConney to be a convicted felon and that he had a prior undercover contact with him does not,
without more, provide the required objective basis for Olson's fear that he and his fellow officers
would be endangered by observing the statutory mandate to wait briefly for a response to their
knock and notice of identity and purpose before going through McConney's screen door. The
record basis for exigency in this case falls far short of carrying the government's burden of
proving exigency; it pales in comparison with the circumstances held in other cases to present
objective bases for claims of exigency based upon "palpable peril." See, e.g., (officers had
information that suspects possessed a shotgun and had been previously convicted of armed
assault against police officers); (officers knew suspect was charged with killing policeman with
a firearm). Indeed, as stated in "courts have generally found reasonable ground for an exception
to the knock-notice requirement only when the inhabitants ... possessed weapons and there was
some indication of a propensity to use those weapons," (officer's knowledge that occupants were
engaged in large-scale drug operation and had five guns in house sufficient to justify
unannounced entry). Compare (officer's knowledge that occupant illegally possessed narcotics
and lawfully owned a gun insufficient to justify belief that he might use it). The record on
exigency here is so much weaker than that relied upon by the courts in the foregoing cases that it
fails even the "mild exigency" test, a test which does not relieve the government of the burden of
proving that "there is a likelihood that the occupants will attempt to escape, resist, destroy
evidence, or harm someone within," .
…

UNITED STATES v. JONES 389. U. S. 347 (2012)
Syllabus:
Updated 3/9/12
The Government obtained a search warrant permitting it to install a Global-Positioning-System
(GPS) tracking device on a vehicle registered to respondent Jones’s wife. The warrant
authorized installation in the District of Columbia and within 10 days, but agents installed the
device on the 11th day and in Maryland. The Government then tracked the vehicle’s movements
for 28 days. It subsequently secured an indictment of Jones and others on drug trafficking
conspiracy charges. The District Court suppressed the GPS data obtained while the vehicle was
parked at Jones’s residence, but held the remaining data admissible because Jones had no
reasonable expectation of privacy when the vehicle was on public streets. Jones was convicted.
The D. C. Circuit reversed, concluding that admission of the evidence obtained by warrantless
use of the GPS device violated the Fourth Amendment.
Held:
1) The Government’s attachment of the GPS device to the vehicle, and its use of that device to
monitor the vehicle’s movements, constitutes a search under the Fourth Amendment.
a) The Fourth Amendment protects the “right of the people to be secure in their persons,
houses, papers, and effects, against unreasonable searches and seizures.” Here, the
Government’s physical intrusion on an “effect” for the purpose of obtaining information
constitutes a “search.” This type of encroachment on an area enumerated in the
Amendment would have been considered a search within the meaning of the Amendment
at the time it was adopted.
b) This conclusion is consistent with this Court’s Fourth Amendment jurisprudence,
which until the latter half of the 20th century was tied to common-law trespass. Later
cases, which have deviated from that exclusively property-based approach, have applied
the analysis of Justice Harlan’s concurrence in Katz v. United States, which said that the
Fourth Amendment protects a person’s “reasonable expectation of privacy,” id., at 360.
Here, the Court need not address the Government’s contention that Jones had no
“reasonable expectation of privacy,” because Jones’s Fourth Amendment rights do not
rise or fall with the Katz formulation. At bottom, the Court must “assure preservation of
that degree of privacy against government that existed when the Fourth Amendment was
adopted.” Katz did not repudiate the understanding that the Fourth Amendment embodies
a particular concern for government trespass upon the areas it enumerates. The Katz
reasonable-expectation-of-privacy test has been added to, but not substituted for, the
common-law trespassory test. Post-Katz cases rejecting Fourth Amendment challenges to
“beepers,” electronic tracking devices representing another form of electronic monitoring
do not foreclose the conclusion that a search occurred here.
c) The Government’s alternative argument—that if the attachment and use of the device
was a search, it was a reasonable one—is forfeited because it was not raised below.

JUSTICE SCALIA delivered the opinion of the Court.
Updated 3/9/12
We decide whether the attachment of a Global Positioning-System (GPS) tracking device to an
individual’s vehicle, and subsequent use of that device to monitor the vehicle’s movements on
public streets, constitutes a search or seizure within the meaning of the Fourth Amendment.
In 2004 respondent Antoine Jones, owner and operator of a nightclub in the District of
Columbia, came under suspicion of trafficking in narcotics and was made the target of an
investigation by a joint FBI and Metropolitan Police Department task force. Officers employed
various investigative techniques, including visual surveillance of the nightclub, installation of a
camera focused on the front door of the club, and a pen register and wiretap covering Jones’s
cellular phone.
I
Based in part on information gathered from these sources, in 2005 the Government applied to the
United States District Court for the District of Columbia for a warrant authorizing the use of an
electronic tracking device on the Jeep Grand Cherokee registered to Jones’s wife. A warrant
issued, authorizing installation of the device in the District of Columbia and within 10 days.
On the 11th day, and not in the District of Columbia but in Maryland, agents installed a GPS
tracking device on the undercarriage of the Jeep while it was parked in a public parking lot.
Over the next 28 days, the Government used the device to track the vehicle’s movements, and
once had to replace the device’s battery when the vehicle was parked in a different public lot in
Maryland. By means of signals from multiple satellites, the device established the vehicle’s
location within 50 to 100 feet, and communicated that location by cellular phone to a
Government computer. It relayed more than 2,000 pages of data over the 4-week period.
The Government ultimately obtained a multiple-count indictment charging Jones and several
alleged coconspirators with, as relevant here, conspiracy to distribute and possess with intent to
distribute five kilograms or more of cocaine and 50 grams or more of cocaine base, in violation
of 21 U. S. C. §§841 and 846. Before trial, Jones filed a motion to suppress evidence obtained
through the GPS device. The District Court granted the motion only in part, suppressing the data
obtained while the vehicle was parked in the garage adjoining Jones’s residence. It held the
remaining data admissible, because “‘a person traveling in an automobile on public
thoroughfares has no reasonable expectation of privacy in his movements from one place to
another.” Jones’s trial in October 2006 produced a hung jury on the conspiracy count.
In March 2007, a grand jury returned another indictment, charging Jones and others with the
same conspiracy. The Government introduced at trial the same GPS derived locational data
admitted in the first trial, which connected Jones to the alleged conspirators’ stash house that
contained $850,000 in cash, 97 kilograms of cocaine, and 1 kilogram of cocaine base. The jury
returned a guilty verdict, and the District Court sentenced Jones to life imprisonment.
The United States Court of Appeals for the District of Columbia Circuit reversed the conviction
because of admission of the evidence obtained by warrantless use of the GPS device which, it

Updated 3/9/12
said, violated the Fourth Amendment. The D. C. Circuit denied the Government’s petition for
rehearing en banc, with four judges dissenting. We granted certiorari.
A.
The Fourth Amendment provides in relevant part that “the right of the people to be secure in
their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not
be violated.” It is beyond dispute that a vehicle is an “effect” as that term is used in the
Amendment. We hold that the Government’s installation of a GPS device on a target’s vehicle,
and its use of that device to monitor the vehicle’s movements, constitutes a “search.”
II
It is important to be clear about what occurred in this case: The Government physically occupied
private property for the purpose of obtaining information. We have no doubt that such a physical
intrusion would have been considered a “search” within the meaning of the Fourth
Amendment when it was adopted. Entick v. Carrington, (1765), is a “case we have described as a
‘monument of English freedom’ ‘undoubtedly familiar’ to ‘every American statesman’ at the
time the Constitution was adopted, and considered to be ‘the true and ultimate expression of
constitutional law’” with regard to search and seizure. In that case, Lord Camden expressed in
plain terms the significance of property rights in search-and seizure analysis:
“Our law holds the property of every man so sacred, that no man can set his foot upon his
neighbour’s close without his leave; if he does he is a trespasser, though he does no
damage at all; if he will tread upon his neighbour’s ground, he must justify it by law.”
Entick, supra, at 817.
The text of the Fourth Amendment reflects its close connection to property, since otherwise it
would have referred simply to “the right of the people to be secure against unreasonable searches
and seizures”; the phrase “in their persons, houses, papers, and effects” would have been
superfluous.
…
Our later cases, of course, have deviated from that exclusively property-based approach. In Katz
v. United States, (1967), we said that “the Fourth Amendment protects people, not places,” and
found a violation in attachment of an eavesdropping device to a public telephone booth. Our later
cases have applied the analysis of Justice Harlan’s concurrence in that case, which said that a
violation occurs when government officers violate a person’s “reasonable expectation of
privacy,” id., at 360.
The Government contends that the Harlan standard shows that no search occurred here, since
Jones had no “reasonable expectation of privacy” in the area of the Jeep accessed by
Government agents (its underbody) and in the locations of the Jeep on the public roads, which
were visible to all. But we need not address the Government’s contentions, because Jones’s
Fourth Amendment rights do not rise or fall with the Katz formulation. At bottom, we must
“assure preservation of that degree of privacy against government that existed when the Fourth

Updated 3/9/12
Amendment was adopted.” Kyllo, As explained, for most of our history the Fourth Amendment
was understood to embody a particular concern for government trespass upon the areas
(“persons, houses, papers, and effects”) it enumerates. Katz did not repudiate that understanding.
Less than two years later the Court upheld defendants’ contention that the Government could not
introduce against them conversations between other people obtained by warrantless placement of
electronic surveillance devices in their homes. The opinion rejected the dissent’s contention that
there was no Fourth Amendment violation “unless the conversational privacy of the homeowner
himself is invaded.” “We do not believe that Katz, by holding that the Fourth Amendment
protects persons and their private conversations, was intended to withdraw any of the protection
which the Amendment extends to the home . . . .”
More recently, in Soldal v. Cook County (1992), the Court unanimously rejected the argument
that although a “seizure” had occurred “in a ‘technical’ sense” when a trailer home was forcibly
removed, id., at 62, no Fourth Amendment violation occurred because law enforcement had not
“invaded the individuals’ privacy,” Katz, the Court explained, established that “property rights
are not the sole measure of Fourth Amendment violations,” but did not “snuff out the previously
recognized protection for property.” As Justice Brennan explained in his concurrence in Knotts,
Katz did not erode the principle “that, when the Government does engage in physical intrusion of
a constitutionally protected area in order to obtain information, that intrusion may constitute a
violation of the Fourth Amendment.” We have embodied that preservation of past rights in our
very definition of “reasonable expectation of privacy” which we have said to be an expectation
“that has a source outside of the Fourth Amendment, either by reference to concepts of real or
personal property law or to understandings that are recognized and permitted by society.” Katz
did not narrow the Fourth Amendment’s scope.
The Government contends that several of our post-Katz cases foreclose the conclusion that what
occurred here constituted a search. It relies principally on two cases in which we rejected Fourth
Amendment challenges to “beepers,” electronic tracking devices that represent another form of
electronic monitoring. The first case, Knotts, upheld against Fourth Amendment challenge the
use of a “beeper” that had been placed in a container of chloroform, allowing law enforcement to
monitor the location of the container. We said that there had been no infringement of Knotts’
reasonable expectation of privacy since the information obtained—the location of the automobile
carrying the container on public roads, and the location of the off-loaded container in open fields
near Knotts’ cabin—had been voluntarily conveyed to the public. But as we have discussed, the
Katz reasonable-expectation-of-privacy test has been added to, not substituted for, the commonlaw
trespassory test. The holding in Knotts addressed only the former, since the latter was not at
issue. The beeper had been placed in the container before it came into Knotts’ possession, with
the consent of the then-owner. Knotts did not challenge that installation, and we specifically
declined to consider its effect on the Fourth Amendment analysis. Knotts would be relevant,
perhaps, if the Government were making the argument that what would otherwise be an
unconstitutional search is not such where it produces only public information. The Government
does not make that argument, and we know of no case that would support it.
The second “beeper” case, United States v. Karo, (1984), does not suggest a different
conclusion. There we addressed the question left open by Knotts, whether the installation of a
beeper in a container amounted to a search or seizure. As in Knotts, at the time the beeper was

Updated 3/9/12
installed the container belonged to a third party, and it did not come into possession of the
defendant until later. Thus, the specific question we considered was whether the installation
“with the consent of the original owner constituted a search or seizure . . . when the container is
delivered to a buyer having no knowledge of the presence of the beeper.” We held not. The
Government, we said, came into physical contact with the container only before it belonged to
the defendant Karo; and the transfer of the container with the unmonitored beeper inside did not
convey any information and thus did not invade Karo’s privacy. That conclusion is perfectly
consistent with the one we reach here. Karo accepted the container as it came to him, beeper and
all, and was therefore not entitled to object to the beeper’s presence, even though it was used to
monitor the container’s location. Jones, who possessed the Jeep at the time the Government
trespassorily inserted the information-gathering device, is on much different footing.
The Government also points to our exposition in New York v. Class, (1986), that “the exterior of
a car . . . is thrust into the public eye, and thus to examine it does not constitute a ‘search.’” That
statement is of marginal relevance here since, as the Government acknowledges, “the officers in
this case did more than conduct a visual inspection of respondent’s vehicle.” By attaching the
device to the Jeep, officers encroached on a protected area. In Class itself we suggested that this
would make a difference, for we concluded that an officer’s momentary reaching into the interior
of a vehicle did constitute a search.
Finally, the Government’s position gains little support from our conclusion in Oliver v. United
States, (1984), that officers’ information-gathering intrusion on an “open field” did not constitute
a Fourth Amendment search even though it was a trespass at common law, id., at 183. Quite
simply, an open field, unlike the curtilage of a home is not one of those protected areas
enumerated in the Fourth Amendment. The Government’s physical intrusion on such an area—
unlike its intrusion on the “effect” at issue here—is of no Fourth Amendment significance.
B.
The concurrence begins by accusing us of applying “18th-century tort law.” That is a distortion.
What we apply is an 18th-century guarantee against unreasonable searches, which we believe
must provide at a minimum the degree of protection it afforded when it was adopted. The
concurrence does not share that belief. It would apply exclusively Katz’s reasonable-expectation
of-privacy test, even when that eliminates rights that previously existed.
The concurrence faults our approach for “presenting particularly vexing problems” in cases that
do not involve physical contact, such as those that involve the transmission of electronic signals.
We entirely fail to understand that point. For unlike the concurrence, which would make Katz
the exclusive test, we do not make trespass the exclusive test. Situations involving merely the
transmission of electronic signals without trespass would remain subject to Katz analysis.
In fact, it is the concurrence’s insistence on the exclusivity of the Katz test that needlessly leads
us into “particularly vexing problems” in the present case. This Court has to date not deviated
from the understanding that mere visual observation does not constitute a search. We accordingly
held in Knotts that “a person traveling in an automobile on public thoroughfares has no
reasonable expectation of privacy in his movements from one place to another.” Thus, even

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assuming that the concurrence is correct to say that “traditional surveillance” of Jones for a 4week
period “would have required a large team of agents, multiple vehicles, and perhaps aerial
assistance,” post, at 12, our cases suggest that such visual observation is constitutionally
permissible. It may be that achieving the same result through electronic means, without an
accompanying trespass, is an unconstitutional invasion of privacy, but the present case does not
require us to answer that question.
And answering it affirmatively leads us needlessly into additional thorny problems. The
concurrence posits that “relatively short-term monitoring of a person’s movements on public
streets” is okay, but that “the use of longer term GPS monitoring in investigations of most
offenses” is no good. That introduces yet another novelty into our jurisprudence. There is no
precedent for the proposition that whether a search has occurred depends on the nature of the
crime being investigated. And even accepting that novelty, it remains unexplained why a 4-week
investigation is “surely” too long and why a drug-trafficking conspiracy involving substantial
amounts of cash and narcotics is not an “extraordinary offense” which may permit longer
observation. See post, at 13–14. What of a 2-day monitoring of a suspected purveyor of stolen
electronics? Or of a 6-month monitoring of a suspected terrorist? We may have to grapple with
these “vexing problems” in some future case where a classic trespassory search is not involved
and resort must be had to Katz analysis; but there is no reason for rushing forward to resolve
them here.

UNITED STATES v. ROSS 456 U.S. 798 (1982)
Syllabus
Updated 3/9/12
In Carroll v. United States, the Court held that a warrantless search of an automobile stopped by
police officers who had probable cause to believe the vehicle contained contraband was not
unreasonable within the meaning of the Fourth Amendment. The Court in Carroll did not
explicitly address the scope of the search that is permissible. In this case, we consider the extent
to which police officers — who have legitimately stopped an automobile and who have probable
cause to believe that contraband is concealed somewhere within it — may conduct a probing
search of compartments and containers within the vehicle whose contents are not in plain view.
We hold that they may conduct a search of the vehicle that is as thorough as a magistrate could
authorize in a warrant "particularly describing the place to be searched."
JUSTICE STEVENS delivered the opinion of the Court.
I
In the evening of November 27, 1978, an informant who had previously proved to be reliable
telephoned Detective Marcum of the District of Columbia Police Department and told him that
an individual known as "Bandit" was selling narcotics kept in the trunk of a car parked at 439
Ridge Street. The informant stated that he had just observed "Bandit" complete a sale and that
"Bandit" had told him that additional narcotics were in the trunk. The informant gave Marcum a
detailed description of "Bandit" and stated that the car was a "purplish maroon" Chevrolet
Malibu with District of Columbia license plates.
Accompanied by Detective Cassidy and Sergeant Gonzales, Marcum immediately drove to the
area and found a maroon Malibu parked in front of 439 Ridge Street. A license check disclosed
that the car was registered to Albert Ross; a computer check on Ross revealed that he fit the
informant's description and used the alias "Bandit." In two passes through the neighborhood the
officers did not observe anyone matching the informant's description. To avoid alerting persons
on the street, they left the area.
The officers returned five minutes later and observed the maroon Malibu turning off Ridge Street
onto Fourth Street. They pulled alongside the Malibu, noticed that the driver matched the
informant's description, and stopped the car. Marcum and Cassidy told the driver — later
identified as Albert Ross, the respondent in this action — to get out of the vehicle. While they
searched Ross, Sergeant Gonzales discovered a bullet on the car's front seat. He searched the
interior of the car and found a pistol in the glove compartment. Ross then was arrested and
handcuffed. Detective Cassidy took Ross' keys and opened the trunk, where he found a closed
brown paper bag. He opened the bag and discovered a number of glassine bags containing a
white powder. Cassidy replaced the bag, closed the trunk, and drove the car to headquarters.
At the police station Cassidy thoroughly searched the car. In addition to the "lunch-type" brown
paper bag, Cassidy found in the trunk a zippered red leather pouch. He unzipped the pouch and
discovered $3,200 in cash. The police laboratory later determined that the powder in the paper
bag was heroin. No warrant was obtained.

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Ross was charged with possession of heroin with intent to distribute, in violation of 21 U. S. C. §
841(a). Prior to trial, he moved to suppress the heroin found in the paper bag and the currency
found in the leather pouch. After an evidentiary hearing, the District Court denied the motion to
suppress. The heroin and currency were introduced in evidence at trial and Ross was convicted.
A three-judge panel of the Court of Appeals reversed the conviction. It held that the police had
probable cause to stop and search Ross' car and that the officers lawfully could search the
automobile — including its trunk — without a warrant. The court considered separately,
however, the warrantless search of the two containers found in the trunk. On the basis
of Arkansas v. Sanders, the court concluded that the constitutionality of a warrantless search of
a container found in an automobile depends on whether the owner possesses a reasonable
expectation of privacy in its contents. Applying that test, the court held that the warrantless
search of the paper bag was valid but the search of the leather pouch was not. The court
remanded for a new trial at which the items taken from the paper bag, but not those from the
leather pouch, could be admitted.
The entire Court of Appeals then voted to rehear the case en banc. A majority of the court
rejected the panel's conclusion that a distinction of constitutional significance existed between
the two containers found in respondent's trunk; it held that the police should not have opened
either container without first obtaining a warrant. The court reasoned:
"No specific, well-delineated exception called to our attention permits the police to
dispense with a warrant to open and search `unworthy' containers. Moreover, we believe
that a rule under which the validity of a warrantless search would turn on judgments
about the durability of a container would impose an unreasonable and unmanageable
burden on police and courts. For these reasons, and because the Fourth Amendment
protects all persons, not just those with the resources or fastidiousness to place their
effects in containers that decision-makers would rank in the luggage line, we hold that the
Fourth Amendment warrant requirement forbids the warrantless opening of a closed,
opaque paper bag to the same extent that it forbids the warrantless opening of a small
unlocked suitcase or a zippered leather pouch."
The en banc Court of Appeals considered, and rejected, the argument that it was reasonable for
the police to open both the paper bag and the leather pouch because they were entitled to conduct
a warrantless search of the entire vehicle in which the two containers were found. The majority
concluded that this argument was foreclosed by Sanders.
Three dissenting judges interpreted Sanders differently. Other courts also have read
theSanders opinion in different ways. Moreover, disagreement concerning the proper
interpretation of Sanders was at least partially responsible for the fact
that Robbins v.California, was decided last Term without a Court opinion.
There is, however, no dispute among judges about the importance of striving for clarification in
this area of the law. For countless vehicles are stopped on highways and public streets every day,
and our cases demonstrate that it is not uncommon for police officers to have probable cause to
believe that contraband may be found in a stopped vehicle. In every such case a conflict is
presented between the individual's constitutionally protected interest in privacy and the public

Updated 3/9/12
interest in effective law enforcement. No single rule of law can resolve every conflict, but our
conviction that clarification is feasible led us to grant the Government's petition for certiorari in
this case and to invite the parties to address the question whether the decision in Robbins should
be reconsidered.
II
We begin with a review of the decision in Carroll itself. In the fall of 1921, federal prohibition
agents obtained evidence that George Carroll and John Kiro were "bootleggers" who frequently
traveled between Grand Rapids and Detroit in an Oldsmobile Roadster. On December 15, 1921,
the agents unexpectedly encountered Carroll and Kiro driving west on that route in that car. The
officers gave pursuit, stopped the roadster on the highway, and directed Carroll and Kiro to get
out of the car.
No contraband was visible in the front seat of the Oldsmobile and the rear portion of the roadster
was closed. One of the agents raised the rumble seat but found no liquor. He raised the seat
cushion and again found nothing. The officer then struck at the "lazyback" of the seat and
noticed that it was "harder than upholstery ordinarily is in those backs." He tore open the seat
cushion and discovered 68 bottles of gin and whiskey concealed inside. No warrant had been
obtained for the search.
Carroll and Kiro were convicted of transporting intoxicating liquor in violation of the National
Prohibition Act. On review of those convictions, this Court ruled that the warrantless search of
the roadster was reasonable within the meaning of the Fourth Amendment. In an extensive
opinion written by Chief Justice Taft, the Court held:
"On reason and authority the true rule is that if the search and seizure without a warrant are made
upon probable cause, that is, upon a belief, reasonably arising out of circumstances known to the
seizing officer, that an automobile or other vehicle contains that which by law is subject to
seizure and destruction, the search and seizure are valid. The Fourth Amendment is to be
construed in the light of what was deemed an unreasonable search and seizure when it was
adopted, and in a manner which will conserve public interests as well as the interests and rights
of individual citizens."
The Court explained at length the basis for this rule. The Court noted that historically warrantless
searches of vessels, wagons, and carriages — as opposed to fixed premises such as a home or
other building — had been considered reasonable by Congress. After reviewing legislation
enacted by Congress between 1789 and 1799, the Court stated:
"Thus contemporaneously with the adoption of the Fourth Amendment we find in the
first Congress, and in the following Second and Fourth Congresses, a difference made as
to the necessity for a search warrant between 806*806 goods subject to forfeiture, when
concealed in a dwelling house or similar place, and like goods in course of transportation
and concealed in a movable vessel where they readily could be put out of reach of a
search warrant."
The Court reviewed additional legislation passed by Congress and again noted that:

Updated 3/9/12
"the guaranty of freedom from unreasonable searches and seizures by the Fourth
Amendment has been construed, practically since the beginning of the Government, as
recognizing a necessary difference between a search of a store, dwelling house or other
structure in respect of which a proper official warrant readily may be obtained, and a
search of a ship, motor boat, wagon or automobile, for contraband goods, where it is not
practicable to secure a warrant because the vehicle can be quickly moved out of the
locality or jurisdiction in which the warrant must be sought."
Thus, since its earliest days Congress had recognized the impracticability of securing a warrant
in cases involving the transportation of contraband goods. It is this impracticability, viewed in
historical perspective, that provided the basis for the Carroll decision. Given the nature of an
automobile in transit, the Court recognized that an immediate intrusion is necessary if police
officers are to secure the illicit substance. In this class of cases, the Court held that a warrantless
search of an automobile is not unreasonable.
In defining the nature of this "exception" to the general rule that "[i]n cases where the securing of
a warrant is reasonably practicable, it must be used," the Court in Carroll emphasized the
importance of the requirement that officers have probable cause to believe that the vehicle
contains contraband.
"Having thus established that contraband goods concealed and illegally transported in an
automobile or other vehicle may be searched for without a warrant, we come now to
consider under what circumstances such search may be made. It would be intolerable and
unreasonable if a prohibition agent were authorized to stop every automobile on the
chance of finding liquor and thus subject all persons lawfully using the highways to the
inconvenience and indignity of such a search. Travellers may be so stopped in crossing
an international boundary because of national self protection reasonably requiring one
entering the country to identify himself as entitled to come in, and his belongings as
effects which may be lawfully brought in. But those lawfully within the country, entitled
to use the public highways, have a right to free passage without interruption or search
unless there is known to a competent official authorized to search, probable cause for
believing that their vehicles are carrying contraband or illegal merchandise."
Moreover, the probable-cause determination must be based on objective facts that could justify
the issuance of a warrant by a magistrate and not merely on the subjective good faith of the
police officers. " `[A]s we have seen, good faith is not enough to constitute probable cause. That
faith must be grounded on facts within knowledge of the [officer], which in the judgment of the
court would make his faith reasonable.'
In short, the exception to the warrant requirement established in Carroll — the scope of which
we consider in this case — applies only to searches of vehicles that are supported by probable
cause. In this class of cases, a search is not unreasonable if based on facts that would justify the
issuance of a warrant, even though a warrant has not actually been obtained.
III
The rationale justifying a warrantless search of an automobile that is believed to be transporting
contraband arguably applies with equal force to any movable container that is believed to be

carrying an illicit substance. That argument, however, was squarely rejected in United
States v. Chadwick.
Updated 3/9/12
Chadwick involved the warrantless search of a 200-pound footlocker secured with two padlocks.
Federal railroad officials in San Diego became suspicious when they noticed that a brown
footlocker loaded onto a train bound for Boston was unusually heavy and leaking talcum
powder, a substance often used to mask the odor of marihuana. Narcotics agents met the train in
Boston and a trained police dog signaled the presence of a controlled substance inside the
footlocker. The agents did not seize the footlocker, however, at this time; they waited until
respondent Chadwick arrived and the footlocker was placed in the trunk of Chadwick's
automobile. Before the engine was started, the officers arrested Chadwick and his two
companions. The agents then removed the footlocker to a secured place, opened it without a
warrant, and discovered a large quantity of marihuana.
In a subsequent criminal proceeding, Chadwick claimed that the warrantless search of the
footlocker violated the Fourth Amendment. In the District Court, the Government argued that as
soon as the footlocker was placed in the automobile a warrantless search was permissible
under Carroll. The District Court rejected that argument, and the Government did not pursue it
on appeal. Rather, the Government contended in this Court that the warrant requirement of the
Fourth Amendment applied only to searches of homes and other "core" areas of privacy. The
Court unanimously rejected that contention. Writing for the Court, THE CHIEF JUSTICE stated:
"[I]f there is little evidence that the Framers intended the Warrant Clause to operate
outside the home, there is no evidence at all that they intended to exclude from protection
of the Clause all searches occurring outside the home. The absence of a contemporary
outcry against warrantless searches in public places was because, aside from searches
incident to arrest, such warrantless searches were not a large issue in colonial America.
Thus, silence in the historical record tells us little about the Framers' attitude toward
application of the Warrant Clause to the search of respondents' footlocker. What we do
know is that the Framers were men who focused on the wrongs of that day but who
intended the Fourth Amendment to safeguard fundamental values which would far outlast
the specific abuses which gave it birth."
The Court in Chadwick specifically rejected the argument that the warrantless search was
"reasonable" because a footlocker has some of the mobile characteristics that support warrantless
searches of automobiles. The Court recognized that "a person's expectations of privacy in
personal luggage are substantially greater than in an automobile," and noted that the practical
problems associated with the temporary detention of a piece of luggage during the period of time
necessary to obtain a warrant are significantly less than those associated with the detention of an
automobile. In ruling that the warrantless search of the footlocker was unjustified, the Court
reaffirmed the general principle that closed packages and containers may not be searched without
a warrant. In sum, the Court in Chadwick declined to extend the rationale of the "automobile
exception" to permit a warrantless search of any movable container found in a public place.
… .

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The Arkansas Supreme Court ruled that the warrantless search of the suitcase was impermissible
under the Fourth Amendment, and this Court affirmed. As in Chadwick, the mere fact that the
suitcase had been placed in the trunk of the vehicle did not render the automobile exception
of Carroll applicable; the police had probable cause to seize the suitcase before it was placed in
the trunk of the cab and did not have probable cause to search the taxi itself. Since the suitcase
had been placed in the trunk, no danger existed that its contents could have been secreted
elsewhere in the vehicle. [ As THE CHIEF JUSTICE noted in his opinion concurring in the
judgment:
"Because the police officers had probable cause to believe that respondent's green suitcase
contained marihuana before it was placed in the trunk of the taxicab, their duty to obtain a search
warrant before opening it is clear under United States v. Chadwick, (1977). . . .
". . . Here, as in Chadwick, it was the luggage being transported by respondent at the time
of the arrest, not the automobile in which it was being carried, that was the suspected
locus of the contraband. The relationship between the automobile and the contraband was
purely coincidental, as in Chadwick. The fact that the suitcase was resting in the trunk of
the automobile at the time of respondent's arrest does not turn this into an `automobile'
exception case. The Court need say no more."
The Court in Sanders did not, however, rest its decision solely on the authority of Chadwick. In
rejecting the State's argument that the warrantless search of the suitcase was justified on the
ground that it had been taken from an automobile lawfully stopped on the street, the Court
broadly suggested that a warrantless search of a container found in an automobile could never be
sustained as part of a warrantless search of the automobile itself. The Court did not suggest that it
mattered whether probable cause existed to search the entire vehicle. It is clear, however, that in
neither Chadwick nor Sanders did the police have probable cause to search the vehicle or
anything within it except the footlocker in the former case and the green suitcase in the latter.
However, was a case in which suspicion was not directed at a specific container. In that case the
Court for the first time was forced to consider whether police officers who are entitled to conduct
a warrantless search of an automobile stopped on a public roadway may open a container found
within the vehicle. In the early morning of January 5, 1975, police officers stopped Robbins'
station wagon because he was driving erratically. Robbins got out of the car, but later returned to
obtain the vehicle's registration papers. When he opened the car door, the officers smelled
marihuana smoke. One of the officers searched Robbins and discovered a vial of liquid; in a
search of the interior of the car the officer found marihuana. The police officers then opened the
tailgate of the station wagon and raised the cover of a recessed luggage compartment. In the
compartment they found two packages wrapped in green opaque plastic. The police unwrapped
the packages and discovered a large amount of marihuana in each.
Robbins was charged with various drug offenses and moved to suppress the contents of the
plastic packages. The California Court of Appeal held that "[s]earch of the automobile was
proper when the officers learned that appellant was smoking marijuana when they stopped
him" and that the warrantless search of the packages was justified because "the contents of the
packages could have been inferred from their outward appearance, so that appellant could not
have held a reasonable expectation of privacy with respect to the contents."

Updated 3/9/12
This Court reversed. Writing for a plurality, Justice Stewart rejected the argument that the
outward appearance of the packages precluded Robbins from having a reasonable expectation of
privacy in their contents. He also squarely rejected the argument that there is a constitutional
distinction between searches of luggage and searches of "less worthy" containers. Justice Stewart
reasoned that all containers are equally protected by the Fourth Amendment unless their contents
are in plain view. The plurality concluded that the warrantless search was impermissible
because Chadwick and Sanders had established that "a closed piece of luggage found in a
lawfully searched car is constitutionally protected to the same extent as are closed pieces of
luggage found anywhere else."
In an opinion concurring in the judgment, JUSTICE POWELL, the author of the Court's opinion
in Sanders, stated that "[t]he plurality's approach strains the rationales of our prior cases and
imposes substantial burdens on law enforcement without vindicating any significant values of
privacy." He noted that possibly "the controlling question should be the scope of the automobile
exception to the warrant requirement," id., at 435, and explained that under that view
"when the police have probable cause to search an automobile, rather than only to search
a particular container that fortuitously is located in it, the exigencies that allow the police
to search the entire automobile without a warrant support the warrantless search of every
container found therein. See post, at 451, and n. 13 (STEVENS, J., dissenting). This
analysis is entirely consistent with the holdings in Chadwick and Sanders, neither of
which is an `automobile case,' because the police there had probable cause to search the
double-locked footlocker and the suitcase respectively before either came near an
automobile." Ibid.
The parties in Robbins had not pressed that argument, however, and JUSTICE POWELL
concluded that institutional constraints made it inappropriate to reexamine basic doctrine without
full adversary presentation. He concurred in the judgment, since it was supported — although not
compelled — by the Court's opinion in Sanders, and stated that a future case might present a
better opportunity for thorough consideration of the basic principles in this troubled area.
That case has arrived. Unlike Chadwick and Sanders, in this case police officers had probable
cause to search respondent's entire vehicle. Unlike Robbins, in this case the parties have squarely
addressed the question whether, in the course of a legitimate warrantless search of an
automobile, police are entitled to open containers found within the vehicle. We now address that
question. Its answer is determined by the scope of the search that is authorized by the exception
to the warrant requirement set forth in Carroll.
IV
In Carroll itself, the whiskey that the prohibition agents seized was not in plain view. It was
discovered only after an officer opened the rumble seat and tore open the upholstery of the
lazyback. The Court did not find the scope of the search unreasonable. Having stopped Carroll
and Kiro on a public road and subjected them to the indignity of a vehicle search — which the
Court found to be a reasonable intrusion on their privacy because it was based on probable cause
that their vehicle was transporting contraband — prohibition agents were entitled to tear open a

Updated 3/9/12
portion of the roadster itself. The scope of the search was no greater than a magistrate could have
authorized by issuing a warrant based on the probable cause that justified the search. Since such
a warrant could have authorized the agents to open the rear portion of the roadster and to rip the
upholstery in their search for concealed whiskey, the search was constitutionally permissible.
In Chambers v. Maroney the police found weapons and stolen property "concealed in a
compartment under the dashboard." No suggestion was made that the scope of the search was
impermissible. It would be illogical to assume that the outcome of Chambers— or the outcome
of Carroll itself — would have been different if the police had found the secreted contraband
enclosed within a secondary container and had opened that container without a warrant. If it was
reasonable for prohibition agents to rip open the upholstery in Carroll, it certainly would have
been reasonable for them to look into a burlap sack stashed inside; if it was reasonable to open
the concealed compartment in Chambers, it would have been equally reasonable to open a paper
bag crumpled within it. A contrary rule could produce absurd results inconsistent with the
decision in Carroll itself.
In its application of Carroll, this Court in fact has sustained warrantless searches of containers
found during a lawful search of an automobile. In Husty v. United States the Court upheld a
warrantless seizure of whiskey found during a search of an automobile, some of which was
discovered in "whiskey bags" that could have contained other goods. In Scher v.United
States, federal officers seized and searched packages of unstamped liquor found in the trunk of
an automobile searched without a warrant. As described by a police officer who participated in
the search: "I turned the handle and opened the trunk and found the trunk completely filled with
packages wrapped in brown paper, and tied with twine; I think somewhere around thirty
packages, each one containing six bottles."In these cases it was not contended that police officers
needed a warrant to open the whiskey bags or to unwrap the brown paper packages. These
decisions nevertheless "have much weight, as they show that this point neither occurred to the
bar or the bench." The fact that no such argument was even made illuminates the profession's
understanding of the scope of the search permitted under Carroll. Indeed, prior to the decisions
in Chadwick and Sanders, courts routinely had held that containers and packages found during a
legitimate warrantless search of an automobile also could be searched without a warrant.
As we have stated, the decision in Carroll was based on the Court's appraisal of practical
considerations viewed in the perspective of history. It is therefore significant that the practical
consequences of the Carroll decision would be largely nullified if the permissible scope of a
warrantless search of an automobile did not include containers and packages found inside the
vehicle. Contraband goods rarely are strewn across the trunk or floor of a car; since by their very
nature such goods must be withheld from public view, they rarely can be placed in an automobile
unless they are enclosed within some form of container. The Court in Carroll held that
"contraband goods concealed and illegally transported in an automobile or other vehicle may be
searched for without a warrant." As we noted in Henry v. United States the decision
in Carroll "merely relaxed the requirements for a warrant on grounds of practicability." It neither
broadened nor limited the scope of a lawful search based on probable cause.
A lawful search of fixed premises generally extends to the entire area in which the object of the
search may be found and is not limited by the possibility that separate acts of entry or opening

Updated 3/9/12
may be required to complete the search. Thus, a warrant that authorizes an officer to search a
home for illegal weapons also provides authority to open closets, chests, drawers, and containers
in which the weapon might be found. A warrant to open a footlocker to search for marihuana
would also authorize the opening of packages found inside. A warrant to search a vehicle would
support a search of every part of the vehicle that might contain the object of the search. When a
legitimate search is under way, and when its purpose and its limits have been precisely defined,
nice distinctions between closets, drawers, and containers, in the case of a home, or between
glove compartments, upholstered seats, trunks, and wrapped packages, in the case of a vehicle,
must give way to the interest in the prompt and efficient completion of the task at hand.
This rule applies equally to all containers, as indeed we believe it must. One point on which the
Court was in virtually unanimous agreement in Robbins was that a constitutional distinction
between "worthy" and "unworthy" containers would be improper. Even though such a distinction
perhaps could evolve in a series of cases in which paper bags, locked trunks, lunch buckets, and
orange crates were placed on one side of the line or the other, the central purpose of the Fourth
Amendment forecloses such a distinction. For just as the most frail cottage in the kingdom is
absolutely entitled to the same guarantees of privacy as the most majestic mansion, so also may a
traveler who carries a toothbrush and a few articles of clothing in a paper bag or knotted scarf
claim an equal right to conceal his possessions from official inspection as the sophisticated
executive with the locked attache case.
As Justice Stewart stated in Robbins, the Fourth Amendment provides protection to the owner of
every container that conceals its contents from plain view. But the protection afforded by the
Amendment varies in different settings. The luggage carried by a traveler entering the country
may be searched at random by a customs officer; the luggage may be searched no matter how
great the traveler's desire to conceal the contents may be. A container carried at the time of arrest
often may be searched without a warrant and even without any specific suspicion concerning its
contents. A container that may conceal the object of a search authorized by a warrant may be
opened immediately; the individual's interest in privacy must give way to the magistrate's official
determination of probable cause.
In the same manner, an individual's expectation of privacy in a vehicle and its contents may not
survive if probable cause is given to believe that the vehicle is transporting contraband. Certainly
the privacy interests in a car's trunk or glove compartment may be no less than those in a
movable container. An individual undoubtedly has a significant interest that the upholstery of his
automobile will not be ripped or a hidden compartment within it opened. These interests must
yield to the authority of a search, however, which — in light of Carroll — does not itself require
the prior approval of a magistrate. The scope of a warrantless search based on probable cause is
no narrower — and no broader — than the scope of a search authorized by a warrant supported
by probable cause. Only the prior approval of the magistrate is waived; the search otherwise is as
the magistrate could authorize.
The scope of a warrantless search of an automobile thus is not defined by the nature of the
container in which the contraband is secreted. Rather, it is defined by the object of the search and
the places in which there is probable cause to believe that it may be found. Just as probable cause
to believe that a stolen lawnmower may be found in a garage will not support a warrant to search

Updated 3/9/12
an upstairs bedroom, probable cause to believe that undocumented aliens are being transported in
a van will not justify a warrantless search of a suitcase. Probable cause to believe that a container
placed in the trunk of a taxi contains contraband or evidence does not justify a search of the
entire cab.
V
Our decision today is inconsistent with the disposition in Robbins v. California and with the
portion of the opinion in Arkansas v. Sanders on which the plurality in Robbins relied.
Nevertheless, the doctrine of stare decisis does not preclude this action. Although we have
rejected some of the reasoning in Sanders, we adhere to our holding in that case; although we
reject the precise holding in Robbins, there was no Court opinion supporting a single rationale
for its judgment, and the reasoning we adopt today was not presented by the parties in that case.
Moreover, it is clear that no legitimate reliance interest can be frustrated by our decision
today. [33] Of greatest importance, we are convinced that the rule we apply in this case is faithful
to the interpretation of the Fourth Amendment that the Court has followed with substantial
consistency throughout our history.
We reaffirm the basic rule of Fourth Amendment jurisprudence stated by Justice Stewart for a
unanimous Court in Mincey v. Arizona, 437 U. S. 385, 390:
"The Fourth Amendment proscribes all unreasonable searches and seizures, and it is a
cardinal principle that `searches conducted outside the judicial process, without prior
approval by judge or magistrate, are per seunreasonable under the Fourth Amendment —
subject only to a few specifically established and well-delineated
exceptions.' Katz v. United States, 389 U. S. 347, 357 (footnotes omitted)."
The exception recognized in Carroll is unquestionably one that is "specifically established and
well delineated." We hold that the scope of the warrantless search authorized by that exception is
no broader and no narrower than a magistrate could legitimately authorize by warrant. If
probable cause justifies the search of a lawfully stopped vehicle, it justifies the search of every
part of the vehicle and its contents that may conceal the object of the search.
The judgment of the Court of Appeals is reversed. The case is remanded for further proceedings
consistent with this opinion.
It is so ordered.