28 CFR § 0.112 - Special deputation.
The Director, United States Marshals Service, is authorized to deputize the following persons to perform the functions of a Deputy U.S. Marshal in any district designated by the Director:
(a) Selected officers or employees of the Department of Justice;
(b) Selected federal, state, or local law enforcement officers whenever the law enforcement needs of the U.S. Marshals Service so require;
(c) Selected employees of private security companies in providing courtroom security for the Federal judiciary;
(d) Other persons designated by the Associate Attorney General pursuant to 28 CFR 0.19(a)(3).