ABSTRACT
A wide variety of police agencies operate within the United States. Primary police functions include service provision, peacekeeping, and crime control, the last of which can be performed either reactively (responding to calls from the citizenry) or proactively (taking the initiative in detecting crime). The Metropolitan Police Force in London was the first formal police institution with general law enforcement duties. In the mid-nineteenth century, beginning with New York City, U.S. cities created uniformed police agencies with general crime control and prevention obligations. These forces were not given strong central administrations, and officers were selected from the communities they served. Later reform efforts (notably by August Vollmer) focused on professionalism, which was expected to produce police better able to withstand improper influences. Police department management varies, and has been impacted by contemporary models such as community policing and CompStat. Several factors influence the actions of police officers, including the characteristics of the community, the police organization, and those of the police officer.
