18 U.S.C. § 3172

As used in this chapter— (1) the terms “judge” or “judicial officer” mean, unless otherwise indicated, any United States magistrate judge, Federal district judge, and (2) the term “offense” means any Federal criminal offense which is in violation of any Act of Congress and is triable by any court established by Act of Congress (other than a Class B or C misdemeanor or an infraction, or an offense triable by court-martial, military commission, provost court, or other military tribunal).