The objective of this study is to provide local law enforcement agencies with guidelines for the collection and dissemination of elements of information required for sound decision making in response to the threat or actual initiation of collective violence. Informal, semi-structured interviews in fourteen selected cities and six State police departments with law enforcement officials who have been, or are likely to be, acting in a key, decision making capacity during an episode of collective violence were conducted to develop recommendations. Four steps were followed: literature survey, consultation with a panel of active law enforcement specialists, field survey, and analysis, interpretation, and review of data. That research resulted in this document, one in a series of five, which outlines for the Patrol Commander the need for guidelines, purpose of guidelines, methods of preparation, basic propositions, discussion of terms, information requirements for prevention and control, planning, training, operation, and evaluation of programs to prevent and control collective violence. Related documents are directed to chiefs of police (CE 000 820), community relations personnel (CE 000 821), intelligence personnel (CE 000 822), and patrol personnel (CE 000 824). (KP)