constable
n. a law officer for a particular area such as a rural township, much like a sheriff (who serves a county) and usually elected, who is responsible for such duties as serving summonses, complaints, subpenas, and court orders, assisting the local court, as well as "keeping the peace." In England this was an exalted position as law enforcement chief for an extensive area, but in the United States the office of constable is a dying breed, like Justice of the Peace.