When a crime scene exhibits evidence of a mental or personality aberration a profile is requested. Profiling first involves a comprehensive study of the nature of the criminal act and the types of persons who have committed this offense and an analysis of the crime scene. Then an indepth examination of the background and activities of the victim and any known suspects is conducted, and the probable motivating factors of all parties involved are formulated. Finally, a description of the perpetrator is developed on the basis of the overt characteristics associated with his/her probable psychological makeup. Information necessary for the development of a profile includes crime-scene photographs, the crime-scene neighborhood and complex, the medical examiner's report, a map of the victim's travels prior to death, a complete investigative report of the incident, and victim background. A survey of the users of the profiling provided by the FBI's Behavioral Science Unit indicated that the profiles had been used to focus the investigation properly and to help locate, identify, and prosecute suspects. Profiling may cause an unknown suspect to reveal himself or a known suspect to reveal his guilt. The research format is suggested for testing the validity of profiling developed by the general public, forensic psychiatrist/psychologists, and professional profilers. The method uses case studies where the profile of the actual offender is known, comparing profiles developed from subjects' crime information actual offenders. Nineteen references are listed.