posses

Posse is a term used to describe a group assembled to assist in enforcing the law or to carry out tasks on behalf of a recognized authority. Traditionally, a sheriff or other law-enforcement official may activate a posse to pursue criminals, maintain order, or execute warrants when insufficient officers are available.

Origins lie in English and American common law. The term derives from the Latin posse, meaning “to be able,” via the medieval English posse comitatus—the power of a county sheriff to summon loyal men to aid in public safety.

In the United States, posses were historically common in frontier and rural contexts, formed by sheriffs or magistrates who deputized able-bodied men as temporary officers. The governance and scope of such deputations have varied by jurisdiction and era. Modern practice generally relies on formal deputized officers or reserve programs; civilian deputization is restricted and tightly regulated due to safety and liability concerns. Some states retain legal provisions for temporary deputization, but actual use is limited and subject to state law and policy.

Important distinction: the Posse Comitatus Act of 1878 prohibits federal military personnel from participating in domestic law enforcement; it is not a license to form posses. The act concerns the use of federal troops, not civilian posses under state authority.

Today the term is most often used metaphorically to describe a group of allies or supporters, or in cinematic and historical contexts to describe frontier-era searches. It remains a legal concept in certain jurisdictions, usually as part of a sheriff’s office power to deputize individuals as needed.