Educing Information: Interrogation - National Intelligence University

According to Leo, the number of interrogation tactics employed by
interrogators in a U.S. police station was one of the only two variables that were
significantly related to the likelihood of a successful interrogation. 361 In Leo’s
study, interrogators employed a median of 5 and a mean of 5.62 tactics per
interrogation, yet used some tactics more than others. 362 The twelve tactics most
commonly used by interrogators were the following (with the percentage of cases
where the tactic was used in parentheses): 363
• Appeal to suspect’s self-interest (88%).
• Confront suspect with existing evidence of guilt (85%).
• Undermine suspect’s confidence in denial of guilt (43%).
• Identify contradictions in suspect’s story (42%).
• Use Behavioral Analysis Interview questions (40%).
• Appeal to the importance of cooperation (37%).
• Offer moral justification/psychological excuses (34%).
• Confront suspect with false evidence of guilt (30%).
• Use praise or flattery (30%).
• Appeal to the detective’s expertise/authority (29%).
• Appeal to the suspect’s conscience (23%).
• Minimize the moral seriousness of the offense (22%).
Leo’s findings reveal that, of these tactics, the four most effective in
eliciting a confession, admission, or incriminating statement were (a) appealing
to the suspect’s conscience (97% success rate), (b) identifying and pointing out
contradictions in the suspect’s denial and story (91% success rate), (c) using
praise or flattery (91% success rate), and (d) offering moral justifications or
psychological excuses for the crime (90% success rate). 364
4. Length of Interrogation: As noted above, Leo found that the length of the
interrogation, along with the number of interrogation techniques used, was the
only statistically significant indicator of the likelihood of obtaining incriminating
information through a confession. 365 Leo’s findings reflect that the longer
interrogators interrogate suspects “the more likely they are to wear the suspect
down and elicit incriminating statements.” 366 Successful interrogations were six
times more likely to last more than one hour than unsuccessful ones (36% vs. 6%),
361
Leo, see note 110, p. 292. The other variable was length of the interrogation, discussed below.
362
Id., p. 277.
363
Id., p. 278.
364
Id., p. 294.
365
Id., p. 292.
366
Id.
172