A grand jury indicts and a U.S. Attorney prosecutes based upon their indictment.
9-2.000 - Authority Of The U.S. Attorney In Criminal Division Matters/Prior Approvals
9-2.030 - Authorizing Prosecution
The United States Attorney is authorized to initiate prosecution by filing a complaint, requesting an indictment from the grand jury, and when permitted by law, by filing an information in any case which, in his or her judgment, warrants such action, other than those instances enumerated in JM 9-2.120.
As you can see, a United States Attorney, outside of a grand jury, starts the process by first filing a complaint.
I believe you blurred the lines there a little bit.
Is your error due to being from Cananda?