Although much progress has been made in establishing local planning units since the 1968 Omnibus Crime Control and Safe Streets Act, many questions remain concerning these agencies' functions and degree of institutionalization. This project first reviewed five studies of criminal justice planning activities which focused on elements related to the planning unit's success, three evaluations of Federal criminal justice demonstration programs which contained planning components, and a research study on the institutionalization of local education programs. Questionnaires were then sent to 495 local criminal justice planning groups from the National Association of Criminal Justice Planners, and 186 were returned in time for analysis. The literature review and survey responses demonstrated that support and cooperation from local government officials, local financial support, and a favorable external planning environment were important factors in progress toward institutionalization. A total of 15 individuals who served on the criminal justice planning boards in California and Virginia were interviewed. Both units were successfully performing tasks associated with comprehensive criminal justice planning, such as developing a regional information and communication system and providing forums for discussion of mutual problems. The interviewees attributed the groups' successes to cooperation among the diverse criminal justice agencies and effective leadership. They viewed the local government's financial support as the critical factor in institutionalization but also cited the importance of a highly qualified leader. This information was used to define the major factors in the institutionalization process, evaluate their impact on institutionalization and each other, and then illustrate these findings in a model. Most factors were interrelated, and feedback processes occurred. Tables, footnotes, and 18 references are included. The appendixes contain the survey questionnaire and materials on the path analytic interpretation of the model depicting the institutionalization process.