Contact Between Jury and Judge. Contact between the jury and judge raises special considerations. A judge has discretion in replying to requests or inquiries from the jury, but should consult counsel before responding and should respond only in open court. Failure to follow this rule is subject to harmless error review.

If a jury in federal court is deadlocked in returning a verdict, the judge may make reasonable inquiries to determine whether the jury is truly deadlocked but, in doing so, may not inquire into the numerical division of the jury or its deliberative processes. A state trial judge's inquiry into the numerical division of the jury may constitute grounds for federal habeas corpus relief if such inquiry is shown to coerce the jury to reach a verdict, but not if the inquiry is “simply to assess the progress.” A judge who concludes that the jury cannot overcome a deadlock may, after informing counsel, declare a mistrial. In Allen v. United States, the Supreme Court approved the trial court's practice of urging a deadlocked jury to make further effort to reach a verdict. Such an instruction is known as an Allen charge, which must not be coercive. Some circuits therefore require the use of modified charges to mitigate against the potentially coercive effect of the original Allen charge language. The amount of time the jury deliberates following the Allen charge, although often a factor, will not itself indicate coercion. Most circuit courts allow successive Allen charges.