In the U.S., the chief law-enforcement officer for the courts in a county.
He is ordinarily elected, and he may appoint a deputy. The sheriff and his deputy have the power of police officers to enforce criminal law and may summon private citizens (the posse comitatus , or "force of the county") to help maintain the peace. The main judicial duty of the sheriff is to execute processes and writ s of the courts. Officers of this name also exist in England, Wales, Scotland, and Northern Ireland. In England the office of sheriff existed before the Norman Conquest (1066).