A hung jury refers to a trial jury that was selected to make a determination of the guilt or innocence of an individual in a criminal trial or make a determination of whether an individual is liable in a civil trial, but is incapable of rendering a verdict due to a division of opinion within the jury.
In the United States, the result of a hung jury is a mistrial. After the mistrial is granted, the case will be retried with a new jury. This retrial does not act as a violation of the prohibition against Double Jeopardy. Most, but not all, jurisdictions in the United States allow for the jury to be given an Allen Charge. An Allen Charge is a reminder from the judge of the importance of the jury coming to a unanimous decision in the name of justice and efficiency in and attempt to try and prevent a hung jury.