Psychology, Use in Courts

Varied Legal Processes

The specific legal contexts and issues to which psychologists and other mental health professionals contribute are many and diverse. Within the criminal arena, participation commonly spans pretrial processes (for example, competency to stand trial or to waive counsel, jury selection), the trial process (for instance, criminal responsibility, eyewitness credibility), and posttrial matters (for example, presentence investigations, mitigating circumstances, competency to be sentenced or executed). In the context of civil law, psychologists are central to civil commitment hearings and to determinations of competency to consent to or refuse treatment. Notable and relevant contexts in which psychology assists family legal processes include [Page 1235]mediation, abuse and neglect proceedings, and child custody evaluations.

Psychologists' Functions

Within these varied frameworks, psychologists may perform one or more of several key functions. Most commonly, judges may permit those qualified as experts to offer testimony concerning factual matters that relate directly to the outcome of a trial or hearing. Drawing on knowledge garnered from clinical observations, tests and measurements, past research and experience, psychologists provide fact finders with professional judgments concerning matters in contention that are psychological in nature. For instance, in cases involving a Not Guilty by Reason of Insanity (NGRI) defense, psychologists offer evaluative opinions as to whether the defendant was suffering from a mental disorder that would indicate the absence of mens rea (that is, guilty mind) and, consequently, relieve the accused of criminal responsibility. In civil commitment hearings, courts appeal to clinicians' expert judgments concerning the presence of mental disorder and their professional opinion as to the existence of grave disability or the likelihood of harm to self or others in the (near) future. This form of participation requires that psychologists make an informed prediction about human behavior—predictions that, overall, have been demonstrably inaccurate and risk unnecessarily depriving citizens of liberty interests.

There are two additional functions entertained by psychologists in the courtroom. These include, first, educating fact finders through testimony about behavioral science research on matters of relevance to the trial or hearing, and second, assisting attorneys through consultation at the pretrial or trial stage of a criminal or civil process. In the first instance, the role of the psychologist is limited to offering summary observations or global statements about scientific knowledge. They do not design this testimony directly to resolve matters in contention; rather, they proffer it to assist fact finders in understanding issues or phenomena that may bear on the final verdict or decision. Examples include educating the judge or jury about the accuracy of eyewitness testimony or the psychological impact of familial arrangements on children.

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