Origin of posse comitatusMedieval Latin posse comitātūs : Medieval Latin posse, power, body of men (from Latin, to be able; see potent) + comitātūs, genitive of comitātus, county, territory of a count; see county.
posse comitatus - Legal Definition
- Power of the county.
- A sheriff may summon citizens to assist him in making an arrest; hence posse in the traditional Old West sense.
- A federal statute prohibiting the Army and Air Force from direct participation in civilian law-enforcement activities.