This manual instructs criminal justice system professionals in the functioning of the CMHDDS and provides guidelines to improve criminal justice personnel's access to the CMHDDS. The manual promotes a more efficient, effective, and appropriate use of the CMHDDS by criminal justice professionals by facilitating an understanding of the interdependent nature of the relationship between the criminal justice system and the CMHDDS. The manual opens with a brief overview of the CMHDDS and a general description of the structure and operation of the typical CMHDDS provider. It then discusses key concepts often used in the CMHDDS, describes indicators that will assist criminal justice professionals in determining whether the services of the CMHDDS should be invoked, suggests ways to facilitate interactions with persons who may need those services, and identifies instances when the criminal justice professional should contact the CMHDDS. Glossary, 11-item bibliography.