18 U.S.C. § 3052 : US Code - Section 3052: Powers of Federal Bureau of Investigation

Search 18 U.S.C. § 3052 : US Code - Section 3052: Powers of Federal Bureau of Investigation

The Director, Associate Director, Assistant to the Director,
Assistant Directors, inspectors, and agents of the Federal Bureau
of Investigation of the Department of Justice may carry firearms,
serve warrants and subpoenas issued under the authority of the
United States and make arrests without warrant for any offense
against the United States committed in their presence, or for any
felony cognizable under the laws of the United States if they have
reasonable grounds to believe that the person to be arrested has
committed or is committing such felony.