In simple words, posse comitatus can be a group of people assigned to act as police for a temporary use. The word borrows from the Latin phrase meaning "power of the county."
Posse comitatus pertains to a universal rule applicable to all males over 15 years of age, on whom a sheriff could call for help in avoiding any kind of civil unrest or disorder. The idea of posse comitatus owes its origin to an old English law, stemming out of a citizen's habitual responsibility to raise an alarm whenever a crime of magnanimous proportion occurred in a village. The hue and cry raised by one person or more would assemble fellow villagers to help the sheriff in nabbing the criminal. There is no solitary national group for posse comitatus and posse members understand that there is no higher law authority than that of the county sheriff.
Posse comitatus pertains to a universal rule applicable to all males over 15 years of age, on whom a sheriff could call for help in avoiding any kind of civil unrest or disorder. The idea of posse comitatus owes its origin to an old English law, stemming out of a citizen's habitual responsibility to raise an alarm whenever a crime of magnanimous proportion occurred in a village. The hue and cry raised by one person or more would assemble fellow villagers to help the sheriff in nabbing the criminal. There is no solitary national group for posse comitatus and posse members understand that there is no higher law authority than that of the county sheriff.