Interrogations-and-Confessions-Handbook

CHAPTER 6
Why do Suspects Confess?
Empirical Findings
In this chapter the empirical studies that have been conducted into the importance,
frequency and causes of confessions are reviewed. To what extent are
the theories presented in Chapter 5 supported by the empirical evidence? This
will also be addressed in this chapter.
Most of the studies into confessions during the past decades have been conducted
in England. In contrast, most of the American studies date back to the
1960s, and these have largely focused on studying the effects of the Miranda
ruling on the frequency with which suspects waive their rights and confess.
There is currently a heated Miranda debate in the USA between Cassell
(Cassell, 1996a, 1996b, 1998a, 1998b, 1999; Cassell & Fowles, 1998), who argues
that the landmark ruling has resulted in many lost confessions and an enormous
social cost, and others (e.g. Leo, 1996a, 1998; Leo & Ofshe, 1998b; 2001;
Leo & White, 1999; Schulhofer, 1998; Thomas, 1998; Weisselberg, 1998), who
dispute Cassell’s claims and arguments.
HOW IMPORTANT ARE CONFESSIONS?
How important are confessions for solving a crime and in securing a conviction
in a court of law? Zimbardo (1967) goes as far as to suggest that more than
80% of all crimes are solved by the suspect making a confession, and once
a confession has been made defendants are seldom acquitted. Is Zimbardo’s
claim an exaggeration? The available evidence suggests that it is. However, the
importance of confession evidence in securing a conviction should not be underestimated.
In England defendants can, and sometimes are, convicted on the
basis of confession evidence alone, even when the validity of the confession is
disputed at trial. In England and Wales there is a general rule that the evidence
of a single witness, including that from the suspect himself, is sufficient to prove
the case (McConville, 1993; Royal Commission on Criminal Justice Report,
1993).
The importance of a confession to the police depends on the strength of
the other evidence against the suspect (McConville, 1993). When the evidence
against suspects is strong, then they are much more likely to confess (Irving &