JM 9-2.040
The United States Attorney may dismiss a criminal complaint without prior authorization from the Criminal Division except in the instances enumerated in JM 9-2.145. However, Rule 48(a), Fed. R. Crim. P., requires leave of court for dismissal of a complaint, as discussed infra. See also JM 9-27.000 (Principles of Federal Prosecution).
If the person charged in a complaint has been bound over for grand jury action, the complaint may be dismissed by the United States Attorney only by leave of court. A court may confer on the United States attorney a blanket authorization to dismiss complaints. If such authorization has not been given, leave of court to dismiss the complaint must be obtained in each particular case.
Whether leave of court is required to dismiss a complaint prior to the defendant being bound over for grand jury action has not been judicially settled. The United States Attorney must be governed by the interpretation of Fed. R. Crim. P. 48(a) given by the court in his district. The view that leave of court is not required to dismiss a complaint prior to the person charged being bound over is supported by the control over complaints given to judicial officers in Rules 4 and 5, Fed. R. Crim. P. Under those rules, a judicial officer may issue a warrant, may discharge a defendant, and may cancel an unexecuted warrant of arrest. It would seem, therefore, that the judicial officer can exercise a like control over a complaint prior to his decision to bind over the defendant and that leave of the court is not required.