POSSE COMITATUS

(Latin: "force of the county"), ancient English institution consisting of the shire's force of able-bodied private citizens summoned to assist in maintaining public order. The posse comitatus, originally raised and commanded by the sheriff, became a purely civil instrument as the sheriff's office lost its military functions. From time to time, legislation gave authority to other peace officers and magistrates to call upon the power of the county. In early times, attendance at the posse comitatus was enforced by the penalty of culvertage, or turntail, involving forfeiture of property and perpetual servitude. Although the primary object of the posse comitatus was then to maintain peace and pursue felons under the command of the sheriff, it was also bound to obey a summons for the military defense of the country. In the United States the posse comitatus was perhaps most important on the Western frontier (there known as a posse), but it has been preserved as an institution in many states. Sheriffs and other peace officers have the authority to summon the power of the county. In some counties it is a crime to refuse assistance. In general, members of a posse comitatus have been permitted to use force if necessary to achieve a posse's legitimate ends, but state laws differ as to the legal liability of one who in good faith aids an officer himself acting beyond his authority.