There are instances wherein a jury that has heard all the information presented at a court trial cannot provide a unanimous decision, which is essential to the resolution of the court hearing. When this event happens, the jury foreman informs the judge of this event through a written communication, and the jury is given a set of instructions to follow so as to provide the jury with a means of arriving at a unanimous decision. This is referred to as an Allen Charge, also known as a dynamite charge.
When juries in court trials are unable to come to a unanimous resolution, the court trial is often declared a mistrial and another hearing is set for another jury to evaluate the case and pass judgment once again. However, a judge may wish to avoid this by providing the jury with a set of instructions that will allow them to re-examine the case once more in the hopes that they arrive at a unanimous decision.
An Allen charge usually comes in the wake of a hung jury. A hung jury means that the jury cannot decide unanimously on a verdict while the disqualification of a juror only leads to mistrial if no suitable alternate juror can be found or if the litigants cannot agree to continue. When a mistrial is called, a retrial is in order for the same issue, but all other matters instigating the mistrial must be resolved.
The Allen charge originated from the case Allen v. United States in 1896, when it was ruled that the judge has the right to encourage a hung jury to reach a unanimous decision through more deliberations.