Suspension of a United States Marshal: Memorandum for Shay Bilchik, Associate Deputy Attorney General [September 23, 1993] [open pdf - 20KB]
"This memorandum will confirm oral advice, given to the Deputy Attorney General and to the Marshals Service, that the Attorney General has the power to suspend a United States Marshal without pay, with the President's prior approval. She may also designate an Acting United States Marshal during the period of the United States Marshal's suspension. This Office has concluded repeatedly that the Attorney General may suspend a United States Marshal without pay, provided that she has the prior approval of the President. The President's power to appoint a United States Marshal entails the power to remove him. […]The President's removal power includes 'the lesser power to place one upon temporary leave without pay as incidental to the power to appoint and dismiss.'"
United States. Department of Justice: http://www.justice.gov/