An officer, generally elected by the people, who possesses power as a conservator of the peace at common law, and by virtue of various legislative enactments.
He may therefore apprehend a supposed offender without a warrant, as treason, felony, breach of the peace, and for some misdemeanors less than felony, when committed in his view. He may also arrest a supposed offender upon the information of others but he does so at his peril, unless he can show that a felony has been committed by some person, as well as the reasonableness of the suspicion that the party arrested is guilty. He has power to call others to his assistance or he may appoint a deputy to do ministerial acts.
A constable is also a ministerial officer, bound to obey the warrants and precepts of justices, coroners and sheriffs. Constables are also in some states bound to execute the warrants and process of justices of the peace in civil cases.
In England, they have many officers with more or less power, who bear the name of constables; such as, lord high constable of England, high constable, head constables, petty constables, constables of castles, constables of the tower, constables of the fees, constable of the exchequer, constable of the staple, etc.
In some of the cities of the United States there are officers called high constables, who are the principal police officers where they reside.