28 U.S.C. § 516: Conduct of litigation reserved to Department of Justice.
28 U.S.C. § 519: Attorney General directs all U.S. Attorneys in the discharge of duties.
28 U.S.C. § 547: Each United States attorney shall prosecute for all offenses against the United States within their district.
Justice Manual § 1-8.000: Principle of non-interference in individual charging decisions.