does a jury all have to agree on a verdict
Hung jury In the United States, the result is a mistrial, and the case may be retried (United States v. Perez, 1824). Some jurisdictions permit the court to give the jury a so-called Allen charge, inviting the dissenting jurors to re-examine their opinions, as a last-ditch effort to prevent the jury from hanging. The Federal Rules of Criminal Procedure state, "The verdict must be unanimous. . . . If there are multiple defendants, the jury may return a verdict at any time during its deliberations as to any defendant about whom it has agreed. . . . If the jury cannot agree on all counts as to any defendant, the jury may return a verdict on those counts on which it has agreed. . . . If the jury cannot agree on a verdict on one or more counts, the court may declare a mistrial on those counts. A hung jury does not imply either the defendant's guilt or innocence. The government may retry any defendant on any count on which the jury could not agree."[8]
Sixth Amendment to the United States Constitution When, under the Fourteenth Amendment, the Supreme Court extended the right to a trial by jury to defendants in state courts, it re-examined some of the standards. It has been held that twelve came to be the number of jurors by "historical accident," and that a jury of six would be sufficient,[5] but anything less would deprive the defendant of a right to trial by jury.[6] The Sixth Amendment mandates unanimity in a federal jury trial. However, the Supreme Court has ruled that the Due Process Clause of the Fourteenth Amendment, while requiring states to provide jury trials for serious crimes, does not incorporate all the elements of a jury trial within the meaning of the Sixth Amendment. Thus, states are not mandated to require jury unanimity, unless the jury has only six members.[7][8][9]