Body of agents organized to maintain civil order and public safety, enforce the law, and investigate crime. Characteristics common to most police forces include a quasi-military organization, a uniformed patrol and traffic-control force, plainclothes divisions for criminal investigations, and a set of enforcement priorities that reflects the community's way of life. Administration may be centralized at the national level downward, or decentralized, with local police forces largely autonomous. Recruits usually receive specialized training and take an exam. The modern metropolitan police force began with Sir Robert Peel in Britain c. 1829. Secret police are often separate, clandestine organizations established by national governments to maintain political and social orthodoxy, which typically operate with little or no restraint.