The study's first phase assesses the adequacy, effectiveness, and efficiency of the existing UCR system and offers a "Background Report," which is included in this report. The project's second phase focuses on the formulation of a strategy for implementing an incident-based law enforcement reporting program. This is recommended in the belief that it will meet the needs of State and local agencies, address the information needs of community groups and other consumers of the data, and comply with the reporting requirements of the National Incident-Based Reporting System (NIBRS). The researchers conclude that the phased implementation of an incident-based offense and arrest reporting system will give data providers, users, and consumers the information necessary to respond effectively to crime. Effective action against crime requires knowledge about current conditions, available alternatives, and the impact of intervention strategies. Incident-based reporting provides the mechanisms with which to build the foundation of knowledge necessary for effective action. Appended discussion of NIBRS data elements and data values