(a) Jury Trial. If the defendant is entitled to a jury trial, the trial must be by jury unless:

(1) the defendant waives a jury trial in writing;

(2) the government consents; and

(3) the court approves.

(b) Jury Size.

(1) In General. A jury consists of 12 persons unless this rule provides otherwise.

(2) Stipulation for a Smaller Jury. At any time before the verdict, the parties may, with the court’s approval, stipulate in writing that:

(A) the jury may consist of fewer than 12 persons; or

(B) a jury of fewer than 12 persons may return a verdict if the court finds it necessary to excuse a juror for good cause after the trial begins.

(3) Court Order for a Jury of 11. After the jury has retired to deliberate, the court may permit a jury of 11 persons to return a verdict, even without a stipulation by the parties, if the court finds good cause to excuse a juror.

(c) Nonjury Trial. In a case tried without a jury, the court must find the defendant guilty or not guilty. If a party requests before the finding of guilty or not guilty, the court must state its specific findings of fact in open court or in a written decision or opinion.