Forensic psychology, a subfield of psychology, involves the application of psychological knowledge and methods to both civil and criminal legal questions. Traditionally, it has a broad definition as well as a narrow definition.[1] The broader classification states that forensic psychology involves the application of all psychological areas of research to the legal field, while the narrower definition characterizes forensic psychology as “The application of clinical specialties to legal institutions and people who come into contact with the law.”[2] While the American Psychological Association (APA) officially recognized forensic psychology as a specialty under the narrower definition in 2001, the Specialty Guidelines for Forensic Psychologists were revised in 2013 and now include all subfields of psychology (e.g. social, clinical, experimental, counseling, neuropsychology) that apply “the scientific, technical, or specialized knowledge of psychology to the law.”[3][4]

In addition to forensic psychology, legal psychology is practiced within the umbrella term of psychology and law as recognized by Division 41 of the APA, American Psychology-Law Society.[5] Legal psychology, as a whole, focuses on many of the aspects that forensic psychology centers around—these being how psychology can be applied to the legal field. As such, these subfields can often be used interchangeably with the exception that legal psychology does not typically include clinical matters within its scope. These issues, in particular those directly relating to mental health, are best explained through forensic psychology.

Because forensic psychology is interlaced with the legal field, it requires an understanding of fundamental legal principles, such as those regarding standard legal practices and standards used by legal professionals, expert witness testimony, competence and insanity definitions and evaluations, and so on in order to be able to communicate effectively with judges, attorneys, and other legal professionals.