This article introduces a more refined conceptualization of the criminal justice involvement of clients of mental health programs than is evident in the existing literature, and demonstrates a research methodology that provides program administrators with standardized measures of program performance in this area. The conceptualization of the criminal justice involvement of people served by community mental health programs distinguishes between three distinct areas of concern: (1) program accessibility to people with a history of criminal justice involvement, (2) criminal justice outcomes, and (3) quality of program performance. The methodology makes use of existing data resources to provide a valid and reliable measure of program performance in these three areas.