A mistrial is a trial that ends before a verdict because a serious problem makes it impossible to continue fairly. It isn’t a finding of guilt or innocence, and the case may be tried again, depending on the circumstances and the law that applies.
Why a mistrial happens
A judge may declare a mistrial when continuing the proceedings would risk an unfair result. Common reasons include:
- A jury can’t agree on a verdict, creating a “hung jury.”
- The jury hears highly prejudicial evidence that shouldn’t have been admitted.
- A lawyer, witness, juror or judge commits serious misconduct.
- A juror has improper contact with someone involved in the case.
- A key participant becomes unavailable because of illness, injury or death.
- An unexpected event disrupts the trial so severely that it can’t proceed.
Either side may ask for a mistrial, but the judge decides whether the problem is serious enough to end the trial.
What happens afterward?
Once a mistrial is declared, the trial is generally treated as legally invalid, and there is no verdict from that proceeding. The prosecutor in a criminal case may often seek a new trial with a different jury, although double-jeopardy rules and the reason for the mistrial can affect whether a retrial is allowed.
A mistrial also doesn’t automatically mean either side won. The prosecution may decide not to retry the case, the parties may reach a plea or settlement, or the court may schedule another trial.
Mistrial vs. dismissal
A mistrial ends a particular trial, but it doesn’t necessarily end the case. A dismissal, by contrast, removes the charges or claims from that court case. Some dismissals allow the matter to be filed again, while others permanently prevent further proceedings. For example, if jurors remain hopelessly deadlocked, the judge may declare a mistrial and the prosecution may request a new trial. If the judge dismisses the case with prejudice, however, the same claim or charge generally can’t be brought again. The exact outcome depends on the jurisdiction and the legal reason for the court’s decision.