First, it examines the sorts of performance measures now being used; they include rates of crime and victimization, assessments of the fear of crime, and various measures of police activity. Second, it examines the tradeoffs among performance measures and the effects that adopting different ones has on police operation and police accountability. Finally, it recommends several principles that police and the public should follow to ensure that police performance is responsibly demonstrated. The author advises that for the police to be responsible to the public's trust, performance evaluation must emphasize outcomes. This is done by making qualitative appraisals of the organizational capability of the police to perform as effective crime prevention requires. The best indicators of what a police organization can do are not response times, arrest rates, and drug seizures. The best measures are program budgets, decentralization of command, systematic searches for "best practices," bottom-up problemsolving, supervisors who facilitate rather than just audit, appointing for skills rather than rank, and information systems that are management-driven. The quality of management is the missing element in most assessments of the performance of police organizations. 30 references