Every British police officer, or constable, has the primary duty of preserving the Queen's peace; specific duties include protecting persons and property, preventing and detecting crime, exercising discretion in prosecuting suspects, and conducting minor prosecutions. Police officers are more than private citizens in uniform, since they may be prosecuted for not performing their law enforcement duties, as a private citizen may not. Constables are accountable for their actions to the law and to their chief constables. However, they take orders from the chief constable only, and not the local authorities or the Crown. The Metropolitan Police Commissioner (MPC) and chief constables are responsible for law enforcement, police policy, and prosecution at their discretion. However, questions arise concerning their accountability. While the MPC is under the authority of the Home Secretary, it is unclear whether the Secretary can give directions for policy, prosecution, and law enforcement, and in fact, does not do so. Although the MCP is answerable to Parliament, it cannot direct the MCP except through legislation. Bodies exercising limited control over chief constables include the local police authorities, composed of public officials; the Home Secretary; Parliament; county councils; the courts and the director of public prosecution. The authority of these bodies over the police is detailed. A total of 45 footnotes is included.