The place and function of forensic sciences personnel in American criminal law and court procedure, and the criteria used by criminal trial judges and lawyers to assess the value of forensic sciences personnel were investigated. Federal, state, Virgin Island, and Puerto Rican laws were examined, and a search of the medical and legal literature provided information on the training of forensic science personnel as related to contemporary criminal justice. A survey questionnaire was mailed to 5,500 practicing criminal court judges and lawyers; a 26% response was obtained. Results showed that (1) judges, lawyers, and police officers lack appreciation of the contribution of the forensic sciences to criminal justice proceedings; (2) defense counsels are often unable to locate or to afford appropriate aid from forensic sciences personnel; and (3) data support the value of the behavioral sciences, such as psychiatry, to law practitioners, especially for sentencing decisions. A brief bibliography, a compilation of individual survey responses, and detailed information from the computer analysis of the survey findings are appended. (Author/MV)