The report mainly reviews literature from North America. Police are popularly viewed as crime fighters, but much of their time is spent on work not specifically related to crime. General patrolling appears to have little or no effect on crime rates, although the targeting of patrols for specific areas or specific crimes may sometimes improve crime control for specific crimes. The detection and clearance of the more common forms of crime depends largely on the public's willingness and ability to report crimes to the police. Although economic, legal, and organizational constraints may hamper police effectiveness, the main constraint on effective policing stems from the nature of crime. The concept of community policing, under which responsibility for crime control is shared by the police and the public, may be the most effective means of fulfilling the wide variety of tasks currently falling to the police. One of the main tasks of future research is to identify ways in which the police and the public can work together to control crime. The present data indicate that a main police responsibility is alleviating the public's fear of crime, which may be more socially harmful than crime itself. While the police may be unable to catch the offender, they should also support the victim, for whom the incident's aftermath may well be more distressing than the incident itself. The police should also educate the public in how to avoid crime and should intervene in street disturbances and domestic disputes to prevent crimes from occurring. Finally, the police should identify the crimes which can be reduced by police activity and should develop tactics to control these crimes. Footnotes and a list of 180 references are provided.