Contrary to popular belief, the word “forensic” does not imply investigations of deceased individuals (although it can in some circumstances). The word comes from the Latin word forensic, which means “of or pertaining to the Forum” which was where the law courts were in the Roman Empire. It refers to any investigation undertaken to assist the legal process. There are forensic engineers, nurses, physicists, physicians, and a host of other subspecialties.

While there is significant overlap between what psychologists and psychiatrists actually do, there are important differences. Psychiatrists are medical doctors who specialize in the treatment of mental disorders through the use of psychotropic medications. Some psychiatrists engage in psychotherapy with patients, but this is becoming less common. Licensed psychologists generally hold doctoral degrees (Ph.D., Psy.D., Ed.D.) in clinical, school or counseling psychology. They do not prescribe medications in most states but instead specialize in psychological testing and psychotherapy. Most psychiatrists do not receive specialized training in psychological testing.

Generally, the decision to retain a forensic psychologist is made through discussions with your lawyer. Forensic psychologists are called into a case by an attorney or by the court when there is a psycho-legal issue that needs to be assessed. Examples include the psychological effects of an injury in a personal injury case, an individual’s ability to parent their children, or whether someone is criminally responsible for their actions in the commission of a crime. Forensic psychologists are also retained as case consultants, for example to review another mental health expert’s report and testimony and give the retaining lawyer information about any problems in that assessment.

All licensed psychologists must follow the ethical standards laid out in the American Psychological Association's (APA) Ethical Principles of Psychologists and Code of Conduct. In addition, the American Psychology-Law Society (Division 41 of the American Psychological Association) has developed an even more specific and detailed set of ethical guidelines (Specialty Guidelines for Forensic Psychology). Finally, many state boards of psychology have special rules and regulations for forensic practice.