JM 9-2.145
Criminal Division approval is required before dismissing, in whole or in part, an indictment, information, or complaint if prior approval was required before seeking an indictment or filing an information or complaint.
The above mentioned approval is not a direction but rather an authorization to dismiss if, in the opinion of the United States Attorney, this course is advisable. United States Attorneys must satisfy themselves that the conditions upon which dismissals are authorized have been complied with.