police, public and private agents concerned with the enforcement of law, order, and public protection. In modern cities their duties cover a wide range of activities, from criminal investigation and apprehension to crime prevention, traffic regulation, and maintenance of records. In many countries they also have a political function (see secret police). The foundations of the present English metropolitan police system were formulated in 1829 by Sir Robert Peel (see Scotland Yard). On the North American frontier, before the government was well organized, vigilance committees (see vigilantes) functioned as volunteer police. The Texas Rangers and the Royal Canadian Mounted Police are examples of organizations that function especially in large, sparsely populated areas. The colonies maintained constables, and this office survives in the rural sheriff. Regular police forces appeared in many states after the establishment (1844) of the New York City organization. Administration of the police system varies in different countries. In Europe, especially on the Continent, it tends to be centralized. In the United States there is decentralization: Metropolitan police have the widest functions, and state police are chiefly concerned with traffic control and rural protection. Police agents of the federal government include members of the Federal Bureau of Investigation, agents of the Dept. of Homeland Security (including the members of the Secret Service, who guard the president and certain other public figures), and agents of the Dept. of Justice. The fight against crime on the international level is coordinated by the International Criminal Police Commission, popularly known as Interpol.
See J. Cramer, The World's Police (1964); H. Hahn, ed., Police in Urban Society (1971); H. K. Becker, Police Systems of Europe (1973); D. H. Bayley, Patterns of Policing: A Comparative International Perspective (1985); J. Roach and J. Thomaneck, ed., The Police and Public Order in Europe (1985); J. D. Brewer et al., The Police, Public Order and the State (1988); D. J. Kenney, ed., Police and Policing (1988).