Forensic psychology applies cognitive psychology research to legal contexts, addressing how human cognitive processes affect the collection, evaluation, and presentation of evidence in the justice system. The field has revealed systematic ways in which normal cognitive processes — not malice or incompetence — can lead to wrongful convictions, unreliable testimony, and flawed legal decision-making. This research has produced reforms in police procedures, courtroom practices, and legal standards.
Cognitive Processes in Legal Contexts
Memory research reveals that eyewitness memory is constructive, malleable, and subject to systematic distortion through leading questions, post-event information, and social influence. Attention research shows that witnesses often miss critical details due to inattentional blindness, change blindness, and weapon focus (attention captured by a weapon at the expense of the perpetrator's face). Decision-making research reveals that jurors are subject to the same cognitive biases as other decision-makers: anchoring effects in damage awards, confirmation bias in evidence evaluation, and hindsight bias in determining negligence.
The Innocence Project has documented that eyewitness misidentification is the leading cause of wrongful convictions, contributing to over 70% of DNA exonerations. Cognitive psychology research has identified the factors that increase misidentification risk: cross-race identification, high-stress encoding conditions, weapon presence, suggestive identification procedures, and post-identification feedback. This research has led to reforms including double-blind lineup administration, unbiased instructions, sequential presentation, and confidence statements at the time of identification.
Expert Testimony
Cognitive psychologists increasingly serve as expert witnesses, educating juries about the limitations of eyewitness memory, the psychology of confessions, and the factors that affect the reliability of testimony. Research shows that jurors generally overestimate the accuracy of confident eyewitnesses, making expert education an important corrective.