Psychologists play various roles in police organizations. They began working directly with the police in the 1960's by providing treatment services. Since the 1970's, the nature of policing has changed. Much of policing now involves the delivery of social services rather than strict law enforcement. For example, police officers must now deal with community relations, minority group issues, domestic violence, and mentally ill individuals. During the past 20 years, police forces have increased their use of psychological tests in police recruit selection. Further, in response to the changing nature of policing, many police forces have modified their training's content and style. There is a clear need for police psychology research, and eyewitness research is the primary focus of forensic research in psychology. Differences between controlled and field research findings are noted, and the application of psychological research to police operations is discussed. 29 references