28 U.S.C. § 566: Powers and duties

It is the primary role and mission of the United States Marshals Service to provide for the security and to obey, execute, and enforce all orders of the United States District Courts, the United States Courts of Appeals, the Court of International Trade, and the United States Tax Court, as provided by law. The United States marshal of each district is the marshal of the district court and of the court of appeals when sitting in that district, and of the Court of International Trade holding sessions in that district, and may, in the discretion of the respective courts, be required to attend any session of court. Except as otherwise provided by law or Rule of Procedure, the United States Marshals Service shall execute all lawful writs, process, and orders issued under the authority of the United States, and shall command all necessary assistance to execute its duties. Each United States marshal, deputy marshal, and any other official of the Service as may be designated by the Director may carry firearms and make arrests without warrant for any offense against the United States committed in his or her presence, or for any felony cognizable under the laws of the United States if he or she has reasonable grounds to believe that the person to be arrested has committed or is committing such felony. provide for the personal protection of Federal jurists, court officers, witnesses, and other threatened persons in the interests of justice where criminal intimidation impedes on the functioning of the judicial process or any other official proceeding; investigate such fugitive matters, both within and outside the United States, as directed by the Attorney General; issue administrative subpoenas in accordance with section 3486 of title 18 , solely for the purpose of investigating unregistered sex offenders (as defined in such section 3486); and assist State, local, and other Federal law enforcement agencies, upon the request of such an agency, in locating and recovering missing children. Nothing in paragraph (1)(B) shall be construed to interfere with or supersede the authority of other Federal agencies or bureaus. In accordance with procedures established by the Director, and except for public money deposited under section 2041 of this title , each United States marshal shall deposit public moneys that the marshal collects into the Treasury, subject to disbursement by the marshal. At the end of each accounting period, the earned part of public moneys accruing to the United States shall be deposited in the Treasury to the credit of the appropriate receipt accounts. a United States marshal shall deliver to the marshal’s successor all prisoners in his custody and all unserved process; and a deputy marshal shall deliver to the marshal all process in the custody of the deputy marshal. The United States marshals shall pay such office expenses of United States Attorneys as may be directed by the Attorney General. The Director of the United States Marshals Service shall consult with the Judicial Conference of the United States on a continuing basis regarding the security requirements for the judicial branch of the United States Government, to ensure that the views of the Judicial Conference regarding the security requirements for the judicial branch of the Federal Government are taken into account when determining staffing levels, setting priorities for programs regarding judicial security, and allocating judicial security resources. In this paragraph, the term “judicial security” includes the security of buildings housing the judiciary, the personal security of judicial officers, the assessment of threats made to judicial officers, and the protection of all other judicial personnel. The United States Marshals Service retains final authority regarding security requirements for the judicial branch of the Federal Government.