Jury Composition and Unanimity.

Juries have historically been composed of twelve persons, but the Supreme Court has held that juries of six or more satisfy the Sixth Amendment. Rule 23(b) of the Federal Rules of Criminal Procedure requires a twelve-member jury. However, Rule 23(b) also permits parties to waive the twelve-member jury requirement at any time before the verdict, provided that the agreement is in writing and approved by the court. Although the Supreme Court has recognized the defendant's right to a unanimous verdict in federal jury trials, Rule 23(b) permits a federal court, at its discretion and without the parties' consent, to accept a verdict by eleven jurors if the twelfth juror is excused for good cause after the jury begins deliberations.