Police Presumption of Guilt Key in False Confessions

November 12, 2002

A police investigator's presumption of a suspect's guilt puts those innocent of crime at greater risk of making false confessions, according to a series of experimental studies by Saul Kassin, professor of psychology and chairman of the legal studies program at Williams College. Kassin presented his findings at the Law and Cognitive Psychology Lecture Series Nov. 8 in a speech titled "Police Interrogations and Confession: Does Innocence Put Innocents at Risk?"

Prof. Saul Kassin said innocent witnesses should invoke their Miranda rights when they feel the police are starting to treat them like a suspect.

Once police secure a signed confession prosecutors are prone to trust in them even when exonerating evidence comes to light. "Once in evidence, a confession is for all practical purposes a conviction," Kassin said.

The Innocence Project at the Cardozo School of Law in New York City, which seeks to obtain the release of those wrongly convicted, has so far won reversals in 114 cases on the basis of new DNA evidence, Kassin said, and in about 25 percent of those cases suspects had made false confessions.

Kassin cited the case of Bruce Godschalk, who falsely confessed to committing two rapes on the same day in King of Prussia, a suburb of Philadelphia, in May 1987. He recanted the confession and later DNA analysis by two separate labs confirmed that Godschalk had not committed the crimes. But the local prosecutor refused to release him, claiming instead that the lab tests were flawed and that he instead believed the detective and the tape-recorded confession.

"The power of confession is such that even prosecutors believe it rather than DNA evidence from two different labs," Kassin said.

Similarly, in the notorious Central Park jogger rape case five black juveniles were each convicted on the basis of graphically detailed confessions given on camera after nearly 40 hours of interrogation that Kassin believes were nonetheless false. The five also retracted their confessions promptly. A convicted serial rapist and murderer, Matias Reyes, later admitted to the crimes, saying he acted alone, and DNA evidence confirmed his guilt. No DNA evidence linked the juveniles to the crime scene.

The basic text on interrogation techniques for police detectives is Criminal Interrogation and Confession, now in its fourth edition. It is "the Bible of interrogation," Kassin said, noting that the U.S. Supreme Court cited the book in its Miranda rights decision. To elicit confessions, it instructs detectives to isolate suspects, confront them with their guilt with dogged persistence, present false evidence (such as faked hair, blood, or fingerprint specimens, phony witnesses or supposedly failed lie detector tests), put the suspect in a state of helplessness where his denials do not achieve escape for him, and present a palatable alternative that minimizes the crime and makes it seem in the suspect's best interest to make a confession.

Typically a detective might suggest that the crime "was probably an accident" or that the suspect was drunk and did not realize what he was doing, Kassin said. Though courts forbid police from making explicit promises of reduced punishment in exchange for cooperation, once a suspect is convinced that police have somehow gathered evidence that points to him, police might strongly imply that a confession will result in a lighter sentence.

False confessions have three types that Kassin called the voluntary, coerced-compliant and coerced-internalized. In voluntary confessions there is no external pressure and they occur typically in high-profile cases. Two hundred people confessed to kidnapping Lindbergh's baby, for example. In coerced-compliant confessions, the confessor knows he is innocent but confesses to get out of the interrogation situation, to get a promised reward or to avoid a threat. Usually they will immediately recant the confession. In coerced-internalized confessions, innocent suspects come to believe they actually committed the crime and that they have repressed all memory of the act.

The key to a false confession is the detective's presumption of the suspect's guilt, Kassin said. Police investigators who have participated in Kassin's studies have defended their practices with comments such as "I've never taken a false confession and I know because everyone who confessed was later convicted," or "I don't get false confessions because I don't interrogate innocent people." Kassin shrugged at the premises of those statements and declined to comment on them.

Nonetheless, his series of experimental studies of false confessions produced the following conclusions: with high levels of confidence, investigators commit false positive errors and presume innocent suspects to be guilty; naively believing in the power of their innocence, suspects waive their Miranda rights; despite plausible and vigorous denials, innocent suspects are subjected to suggestive and highly aggressive interrogations; the introduction of false evidence increases chances of false confessions; and police "overbelieve" false confessions.

In one study one group of college students were told to fake crimes such as shoplifting, chalking obscenities on walls or breaking into college buildings and setting off alarms. A control group was told to simply appear at the scenes of the phony crimes. All students were then interrogated on videotape and the tapes shown to untrained college students and experienced police investigators from Florida and Toronto. The police professionals identified guilty students correctly 50 percent of the time, no better than chance, but had 80 percent confidence in their judgment. College students who judged the tapes scored lower on accuracy but were also less confident of their judgments. "Where the police made errors, the errors were false positives," Kassin said, who also noted a police bias toward a guilty response. "Some individual investigators, however, do do well and are more highly accurate. We don't know what it is these people are doing."

In another study, Kassin found that about 80 percent of innocent people will waive their Miranda rights, especially people who have never been in trouble before, but only 36 percent of guilty suspects will be persuaded to give up their protection. Police have developed techniques for eliciting waivers that try to make suspects see the police as their ally who cannot help until the formality of Miranda rights is removed. What was shocking, Kassin said, was that in the experiment 67 percent of innocent suspects surrendered their rights in the face of clearly hostile interrogations. "They believed in the power of their innocence to set then free. They believed they could make others see their inner states if they were given long enough."

In an experiment where two-thirds of suspects were expected to be guilty, Kassin found that investigators showed more aggressive presumption of guilt. All participants in the experiment, the interrogators, the suspects and third-party observers agreed that in cases where the suspect was indeed innocent, interrogators exhibited the highest expectation of guilt and exerted the most extreme pressure to get a confession. "Innocence is a risk factor," Kassin said.

In still another experiment Kassin tested police confidence in the confessions they elicited. College students and police detectives were shown real and false confessions and asked to discriminate. College students had a higher degree of accuracy but less confidence in their judgment. "Police investigators are prone to see deception," Kassin said. "But their bias is not to deception, but guilt." Interrogation training increased the level of the response bias, he added.

Asked if his studies suggest that one should invoke one's Miranda rights anytime one is interviewed by police, Kassin said, "I would invoke my rights right from the start. When you think you've shifted from being a witness to being a suspect, you should invoke immediately. Police aren't trusting either the 20 percent who don't waive their rights or the 80 percent who do."

In many cases of bad confessions, he said, there is no other evidence for police to proceed on. They therefore apply very great pressure on suspects for confessions.

The Law and Cognitive Psychology Lecture Series will next present Shari Seidman Diamond, Howard J. Trienens Professor of Law and Professor of Psychology at Northwestern University Law School. Professor Diamond will speak at the Law School on Feb. 27, 2003, on jury room conversation. The series is co-chaired by professor John Monahan of the Law School and U.Va. associate professor of psychology Bobbie Spellman. Professor Kassin's visit was made possible by the Law School's Intellectual Enrichment Fund.

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