The Impact of Gruesome Photographs on Forensic Judgments of Competency and Legal Insanity

The legal system relies heavily on the contribution of forensic psychologists. These psychologists give opinions on a defendant’s ability to stand trial, their legal sanity at the time of the crime, their future dangerousness, and their competency to be executed. However, we know little about what extrinsic factors bias these experts. I assessed the influence of gruesome photographs on forensic psychologists’ evaluations of competency and legal sanity. Previous research has demonstrated that these photographs influence lay judgments of guilt. I predicted that gruesome color photographs (versus the same photographs in black-and-white or a textual description of the photographs) would influence forensic psychologists to judge the defendant competent and sane (decisions that might ultimately lead to punishment). I also predicted that this effect would be greater for sanity judgments than for competency judgments. I asked laypeople to make the same decisions in order to compare expert and lay judgments. I predicted that impact of photograph type seen in experts would be greater in the lay sample. No differences in judgments of competence, sanity, or mental illness emerged as a function of the type of visual information, for either expert or lay participants. Experts relied on competency evidence to make competency judgments and insanity evidence to make insanity judgments. In contrast, lay people relied on various types of evidence to make their ultimate judgments. This research suggests that people making competency and sanity judgments might not be biased by gruesome photographs.