Brief of Amici Curiae, A Group of Concerned Scientists, Texas v. Cielencki

Abstract

Confronting a suspect with a failed or inconclusive polygraph is deceptive and presents a grave and demonstrated risk of eliciting a false confession. Polygraph examinations are predicated on the flawed assumption that innocent individuals will be more disturbed by comparison questions dealing with minor misdeeds than relevant questions about the crime. However, individuals administering polygraph tests often fail to consider that relevant questions might trigger a strong physiological response in an innocent person, just as likely as in a guilty person. Furthermore, the polygraph tests are also flawed because the examiner is the lie detector, meaning that the outcome of the polygraph can and often is tainted by the examiner’s confirmation bias. Studies have shown that in cases where the examinee is found to have failed the polygraph, or the examiner found the results to be inconclusive an innocent person may come to believe that he or she committed the crime and falsely confess. Many courts have recognized that leveraging the results of a polygraph to extract a confession is a coercive tactic that seriously undermines any claim that the defendant’s confession was voluntarily made. Lately, courts have been suppressing confessions made after a suspect was advised that the suspect failed a polygraph, and confessions made after the suspect was told that he or she failed a polygraph when, in fact, the suspect passed, or the results were inconclusive.

Keywords: polygraph, wrongful convictions, false confessions, innocence