Posse comitatus  The posse comitatus, in common law, is a group of people mobilized by the conservator of peace – typically a sheriff – to suppress lawlessness or defend the county. The "posse comitatus" originated in ninth century England simultaneous with the creation of the office of sheriff. Though generally obsolete throughout the world, it remains theoretically, and sometimes practically, part of the United States legal system. The term derives from the Latin "posse comitātūs" ("force of the county"), in English use from the late 16th century, shortened to "posse" from the mid-17th century. While the original meaning refers to a group of citizens assembled by the authorities to deal with an emergency (such as suppressing a riot or pursuing felons), the term is also used for any force or band, especially with hostile intent, often also figuratively or humorously. In 19th-century usage, "posse comitatus" also acquired the generalized or figurative meaning. In classical Latin, "posse" is a contraction of "potesse", an irregular Latin verb meaning "to be able". The unusual genitive in ""-ūs"" is a feature of the fourth declension. In its earliest days the "posse comitatus" was subordinate to king, country and local authority. In 1642, during the early stages of the English Civil War, local forces were employed everywhere and by all sides. The powers responsible produced valid written authority, inducing the locals to assemble. The two most common authorities used were the Militia Ordinance on the side of the Parliamentarians and that of the king, the old-fashioned Commissions of Array. But the Royalist leader in Cornwall, Sir Ralph Hopton, indicted the enemy before the grand jury of the county as disturbers of the peace, and had the "posse comitatus" called out to expel them. The powers of sheriffs in England and Wales for "posse comitatus" were codified by section 8 of the Sheriffs Act 1887, the first subsection of which stated that:  This permitted the sheriff of each county to call every civilian to his assistance to catch a person who had committed a felony—that is, a serious crime. It provided for fines for those who did not comply. The provisions for "posse comitatus" were repealed by the Criminal Law Act 1967. The second subsection provided for the sheriff to take "the power of the county" if he faced resistance while executing a writ, and provided for the arrest of resisters.