DSS's are an important tool for computer-based information systems of law enforcement agencies because of their increasing dependence on computers to manage much of their data and produce an increasing amount of their information. DSS's are divided into two general types (data and model-oriented) and are further separated into six specific categories. Three data-oriented categories are file drawer, data analysis, and analysis information systems. Representational, optimization and suggestion models are termed model-oriented categories or systems. The latter are used to simulate situations and events and suggest courses of action, alternatives, and decisions. Although the three data-oriented systems are somewhat similar to an EDP system, several features make them different. These features are described, and examples of both data- and model-oriented law enforcement DSS's are cited. It is claimed that individual agencies should easily identify with the examples given for data-oriented systems because most have systems similar to the ones described. Identification with model-oriented systems, however, is believed more difficult because DSS's are not in widespread use in law enforcement, they are difficult to understand, and priorities for computerization often exclude DDS applications. It is concluded that the framework of EDP and DDS data processing tools presented will help agencies map the development of their systems, determine what areas conducive to computerization are being emphasized, and which are lacking, and recognize the planning considerations necessary for expansion into the DSS area. Four figures and twelve references are provided.