19 U.S.C. § 1589a — Enforcement authority of customs officers

Subject to the direction of the Secretary of the Treasury, an officer of the customs may— (1) carry a firearm; (2) execute and serve any order, warrant, subpena, summons, or other process issued under the authority of the United States; (3) make an arrest without a warrant for any offense against the United States committed in the officer's presence or for a felony, cognizable under the laws of the United States committed outside the officer's presence if the officer has reasonable grounds to believe that the person to be arrested has committed or is committing a felony; and (4) perform any other law enforcement duty that the Secretary of the Treasury may designate.