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?
Individual US States are a party to some of these lawsuits, and they have their own duly sworn law enforcement officers. I bet a Federal judge would be able to find NY State Troopers or Massachusetts State Police willing to enforce their orders if there is a judgement in favor of that State in court.
Correct - the states have the explicit duty to raise and regulate militias, as stated in the second amendment.
Why would New York cops go after their own like that?