The judge handling a felony federal case is called a district judge or district court judge. District court judges are appointed by the President and confirmed by the Senate in accordance with Article III of the United States Constitution.
District court judges have lifetime appointments and do not have to be reappointed or run for reelection; their salary cannot be reduced once in office. These measures were intended to insulate district judges from political pressures. District court judges do not answer to anyone; however, decisions by district court judges can be appealed to circuit courts of appeal and ultimately the United States Supreme Court.
Federal crime magistrates
Assisting the district court judges are magistrate judges. Magistrate judges handle the initial court appearances in felony cases and are authorized to adjudicate misdemeanor and petty offenses. The first appearances (arraignment, bail, preliminary examination) in a felony case are probably going to be presided over by a magistrate judge.
For a felony, however, the law requires that the trial OR sentencing must be before a district court judge unless the defendant and the prosecutor stipulate or agree to have the matter handled by the magistrate judge. Magistrate judges are selected by the district court judges and serve eight year terms.


