Policing is viewed quite broadly, particularly in relation to diverse ways that public and private protection and security function in contemporary societies, and policing varies in terms of organization, legal mandate, and territorial jurisdiction. Further, substantial organizational specialization occurs within regional and large police departments, and specialized units vary in the scope of crime prevention activities. A common sense view of crime is that a visible police presence prevents people from committing crimes, either individually or in groups. Empirical studies, however, do not provide sufficient information on the role of police visibility in crime prevention. Somewhat paradoxically, both covert and visible policing can be used to prevent victimization by certain crime types. Surveillance is integral to protecting public and private interests, and most agencies with legal mandates to develop surveillance systems do so primarily to detect perpetrators as they are about to commit or actually commit a crime. The legitimate use of authority and coercion is a crime prevention technique, and dispute settlement is a primary concern of police since disputes can escalate into violent crimes. Other facets of crime prevention are examined, including access control, intelligence collection and analysis, research and development, police participation in community crime prevention programs and multiagency crime prevention efforts, problem-solving, and community policing. An examination of the role of private and public police in crime prevention suggests that private policing is more likely to focus on preventing a small range of particular crimes than community-based public police organizations. 80 references and 35 notes