Posse comitatus is a Latin phrase meaning “the power of the county.” Posse comitatus describes a group of citizens who are called upon to assist a sheriff in keeping the peace, to conduct a rescue, or to apprehend a criminal. The ability of a sheriff to assemble a posse and even the extent of powers that a sheriff can delegate to that posse vary depending on the jurisdiction. Some posses engage in volunteer services while others can act as reserve police officers, if needed.
California in particular has various statutes governing posses. For example, any person who assists a police officer in law enforcement activities and is not an independent contractor is considered to be a public employee and is thus entitled to compensation for their efforts. If a person in a posse comitatus is injured or killed while performing the requested law enforcement activity, they are to be indemnified at a rate of up to four times his or her average annual earnings, inclusive of any posse comitatus compensation. At the discretion of a sheriff, as many people as deemed necessary to assist in law enforcement may potentially be recruited, subject to no limitations. Most recently, SB-192 decriminalized the refusal to participate in a posse comitatus, which formerly was a misdemeanor and carried an accompanying fine.
[Last updated in July of 2020 by the Wex Definitions Team]