Federal prosecutors represent the interests of the U.S. and prosecute offenders of federal crimes
Federal prosecutors are part of the Attorney General’s Office, which ultimately reports to the Department of Justice. There is a U.S. Attorney for each federal court district in the United States.
Much of the prosecutorial work is handled by Assistant U.S. Attorneys. The United States Attorney’s Office hires them, and they are subject to the internal policies of the Justice Department and the laws of the United States.
If a trial is necessary, one of the Assistant U.S. Attorneys will likely prosecute the case on behalf of the Federal government.