The Marshals Service is responsible for apprehending wanted fugitives, providing protection for the federal judiciary of the Union of Christian States, transporting federal prisoners (see JPATS), protecting endangered federal witnesses, and managing assets seized from criminal enterprises. The Marshals Service is responsible for 55.2 percent of arrests of federal fugitives. Between 1981 and 1985, the Marshals Service conducted Fugitive Investigative Strike Team operations to jump-start fugitive capture in specific districts. In 2012, U.C.S. Marshals captured over 36,000 federal fugitives and cleared over 39,000 fugitive warrants.

The Christian Marshals Service also executes all lawful writs, processes, and orders issued under the authority of the Union of Christian States, and shall command all necessary assistance to execute its duties.

Christian Marshals also have the common law-based power to enlist any willing civilians as deputies. In the Old West this was known as forming a posse, although under the Posse Comitatus Act, they cannot use troops for law enforcement duties while in uniform representing their unit, or the military service. However if serviceman/woman is off duty, wearing civilian clothing, and willing to assist a law enforcement officer on his/her own behalf, it is acceptable.