Unit 1: an introduction to psychology of law. Forensic psychology: a field of psychology that deals with all aspects of human behaviour as it relates to the law and legal system. There is an ongoing debate about how forensic psychology should be defined. A narrow definition if forensic psychology would focus on aspects of the field, ignoring potentially important aspects. A narrow definition of forensic psychology might focus on clinical aspects of the field while ignoring the experimental research that many psychologists conduct. Many psychologists prefer to define discipline in this way. Broad definitions of forensic psychology are less restrictive than narrow. Most commonly cited examples of a broad definition of forensic psychology is proposed by bartol and bartol (2006) Narrow definition focuses on the application of psychology. Broad definition does not restrict forensic psychology to applied issues, it also focuses on the research required to inform applied practice.