Confessions have a powerful ability to sway the minds of judges and jurors. Yet there are many documented examples of manipulative tactics used by law enforcement personnel to elicit false confessions from people who are not guilty of the crime they are accused of. Defenders of these techniques fail to realize that law enforcement cannot reliable distinguish between a true and false confession, the safeguards already in place do not protect people from making false confessions and people can be made to readily confess to crimes they did not commit. Even judges and jurors are not able to resist the psychological influence of confessions, even when they are legally proven to be coerced. Even worse, false confessions taint other evidence and even make trained professionals change their previous correct interpretations of evidence. Kassin (2008) demolishes some of these myths about confessional evidence.
Fact #1: Law enforcement cannot reliable distinguish truth from lies
One of the most popular police manuals, Criminal Interrogations and Confessions, promote the idea that law enforcement can ask suspects a list of questions, study their behavioral responses and make decisions about the truth status of the claims made by the suspect with a high degree of accuracy. Proponents claim that this method is correct in 85% of cases. However, that study had no means of gauging the actual truth of the criminal cases tested and no control group was used. Furthermore, research has shown that the alleged signs of deception (such as being nervous, not looking the interrogator in the eyes) are not supported by empirical and training in these methods does not provide a considerable increase accuracy for detecting deception above the average 54% baseline of laypeople (which, of course, means that they are only marginally better than flipping a fair coin). To add insult to injury, people trained in this method have been shown to be less accurate and more confident, betraying an increasing susceptibility to confirmation bias. When this study methodology was replicated with trained law enforcement, the results were largely the same.
Fact #2: Legal safeguards, such as Miranda rights, do not protect people from false confessions
“You have the right to remain silent..” is a statement that is often heard on television crime dramas when the police arrest a suspect. It is design to make sure that the suspect are aware of his or her constitutional rights to avoid self-incrimination and a legal counsel. In reality, around 80% of people waive these rights, either because they do not understand them or because they think it serves their own interest. Astonishingly, almost 70% of people waive their constitutional rights even when the interrogator is being aggressive and impervious to contrary evidence. Thus, Miranda rights do not protect people from dangerous interrogation practices.
Fact #3: People confess to crimes they did not commit
The most common method of getting suspects to confess is called the Reid technique. It combines a hostile interrogation approach based on the assumption of guilt and manipulation with manufactured evidence with attempts to offer sympathy and minimize the crime by creating moral rationalizations for why the suspect allegedly carried out the crime. There are countless of documented cases when the Reid technique combined with post-polygraph failure feedback has been used to manipulate people into confessing, even though they were later exonerated by DNA evidence. Other lab experiments that introduce false evidence show that you can essentially double the proportion of people who confess. The alt key paradigm is based on letting a subject fill out a survey on a computer, but instructing him or her that pressing the alt key will make the computer crash and ruin their research. At the baseline, about 50% of students confess to crashing the computer when they did not press the key. If a confederate is introduced who testifies that the subject did indeed press the alt key, the proportion of people who falsely confess jumps to 94%. Countless variations of the basic research design has been done, such as gauging the memories of the subjects (that show that they do not only falsely confess, but create a false memory of committing the crime) and the introduction of heavy fines to make the situation more realistic. Astonishingly, U. S. criminal courts still allow the usage of false evidence to elicit confessions from suspects.
Fact #4: Judges and jurors cannot reliably spot a false confession
Studies on mock jurors show that confessions have an extraordinary high impact of decisions and even when conclusively proven to be coerced, jurors are not able to discount their influence and thus cases where coerced confessions are presented and jurors are explicitly instructed to ignore it have a higher conviction rate than the exact same cases without a confession. Kassin quotes Drizin and Leo (from a 2004 publication) as saying that confessions are “inherently prejudicial and highly damaging to a defendant, even if it is the product of coercive interrogation, even if it is supported by no other evidence, and even if it is ultimately proven false beyond any reasonable doubt”.
So why are jurors unable to disregard confessions that have legally been proven to be false? Kassin offers four explanations: (1) fundamental attribution error (the cognitive bias whereby people overestimate personal factors and underestimate situational factors when judging an event occurred to another person) and thus trust others when it comes to the indulgence of information that runs counter to the other person’s self-interest, (2) people are bad at detecting deception and (3) false confessions are peppered with other information that conforms with people’s opinion on what truthfulness looks like, such as ideas about motives, apologies and extensive details of the crime scene. The authors of the police manual above even suggests that law enforcement introduce errors into the written confession so that the suspect will correct it, thereby enhancing the appearance of credibility and truth.
Fact #5: It is difficult to determine whether a false confession was harmless or not
The last ditch-case for the current interrogation system is that the appeals courts can fix any mistakes made by law enforcement or by the legal system. However, a false confession can artificially enhance the convincing power of other pieces of evidence, even when that “evidence” is based on pseudoscience or lacks diagnostic value. A lab study of a real criminal case used four groups: a control group who got the real story, a group who got a false confession, a group that got an irrelevant testimony by law enforcement about the emotional state of the suspect and the fourth group got both the false confession and the irrelevant testimony. The base rate conviction rate was 53%, false confession increased it to 63%, irrelevant testimony reduced ti to 48%, but the combination of a false confession and the irrelevant testimony boosted the conviction rate to almost 90%. Even trained fingerprint analysts can be swayed by tainted evidence. Almost 20% of them reversed decision on whether or not the fingerprint matched based on hearing that a confession was made or that the suspect was arrested when the crime was committed.
How to combat pseudoscientific myths about confession?
Kassin provides two suggestions for reducing the problems with false confessions:
(1) give psychological science a stronger role in expert testimony so that judges and jurors are aware of the problems with false confessions.
(2) make sure that legal personnel observe the way the confession was produced by taping them from start to finish so they have a first-hand account of the suspects’ cognitive condition and how the interrogation was carried out.
Kassin, S. (2008). Confession Evidence: Commonsense Myths and Misconceptions. Criminal Justice and Behavior, 35 (10), 1309-1322. (PDF)