Federal Rules of Criminal Procedure - Rule 31. Jury Verdict
The jury must return its verdict to a judge in open court. The verdict must be unanimous.
(b) Partial Verdicts, Mistrial, and Retrial.
(1) Multiple Defendants.
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.
(2) Multiple Counts.
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.
(3) Mistrial and Retrial.
If the jury cannot agree on a verdict on one or more counts, the court may declare a mistrial on those counts. The government may retry any defendant on any count on which the jury could not agree.
(c) Lesser Offense or Attempt.
A defendant may be found guilty of any of the following:
(1) an offense necessarily included in the offense charged;
(2) an attempt to commit the offense charged; or
(3) an attempt to commit an offense necessarily included in the offense charged, if the attempt is an offense in its own right.
(d) Jury Poll.
After a verdict is returned but before the jury is discharged, the court must on a party's request, or may on its own, poll the jurors individually. If the poll reveals a lack of unanimity, the court may direct the jury to deliberate further or may declare a mistrial and discharge the jury.