(1)The United States Marshals Service is authorized to—
(A)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;
(B)investigate such fugitive matters, both within and outside the United States, as directed by the Attorney General;
(C)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
(D)assist State, local, and other Federal law enforcement agencies, upon the request of such an agency, in locating and recovering missing children.
https://www.law.cornell.edu/uscode/text/28/566
We can all learn!
(1)The United States Marshals Service is authorized to— (A)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; (B)investigate such fugitive matters, both within and outside the United States, as directed by the Attorney General; (C)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 (D)assist State, local, and other Federal law enforcement agencies, upon the request of such an agency, in locating and recovering missing children.
That's pretty much what I said. They dont make arrests and they protect people but especially when they are moving.