Yes, the US Marshall Service is part of the Department of Justice.
https://en.wikipedia.org/wiki/United_States_Marshals_Service
And, although they operate under the direction of the Attorney General, the following brings up an interesting point:
The Marshals Service serves as the enforcement and security arm of the U.S. federal judiciary
If the court issues an order and the attorney general subsequently refuses to enforce that order, couldn’t the court then issue an order placing the attorney general under arrest?
They take the same Oath everyone else does. Not that that means anything, apparently, but maybe someone may take it seriously, some day.
I don’t believe a single cop out there has ever taken their oath seriously. ACAB