Definition
Forensic psychology is the application of psychological theory, research, and assessment to the legal system — encompassing how crime develops, how investigations are conducted, how evidence is judged, how courts decide, and how offenders are managed after sentencing. It sits at the intersection of behavioural science and law, and its findings are intended to be used by police, lawyers, judges, juries, parole boards, and prison services.
The field is broader than the popular image of an expert profiler in a darkened room. It includes the cognitive psychology of memory and perception (eyewitnesses), the developmental psychology of antisocial behaviour, the clinical psychology of mental-state evaluations, the social psychology of jury reasoning, and the statistical science of risk assessment. The unifying thread is the use of empirical methods to answer questions the legal system would otherwise answer with intuition.
Why it matters
Where it shows up
Forensic psychologists work as expert witnesses, police consultants, prison clinicians, parole-board assessors, and academic researchers. They evaluate competency to stand trial, assess risk of recidivism, advise on interview techniques, design and audit offender-treatment programmes, and contribute behavioural analysis to live investigations.
Just as importantly, they critique the practices of others: forensic psychology has been responsible for major reforms in line-up procedures, interrogation techniques, and the admissibility of expert testimony, by showing where common practice produces unreliable results.