Mistrial
A trial that is declared invalid by the judge before a verdict is reached, usually requiring the case to be tried again.
A mistrial occurs when a judge ends a trial before the jury or judge reaches a verdict. This can happen for many reasons, including juror misconduct, a hung jury (jurors cannot agree on a verdict), improper evidence being presented, or an attorney violating court rules in a way that seriously prejudices the other side. When a mistrial is declared, it is as if the trial never happened.
After a mistrial, the case is not automatically dismissed. The prosecution or plaintiff can typically retry the case. In criminal cases, the question of double jeopardy – whether the defendant can be tried again – depends on why the mistrial was declared. If the mistrial was caused by a “manifest necessity” (such as a hung jury), retrial is generally allowed. If the prosecution caused the mistrial through misconduct, retrial may be barred.
Why it matters: A mistrial means delay, additional expense, and uncertainty for everyone involved. For defendants in criminal cases, understanding when double jeopardy protections apply is important. A mistrial does not mean the charges go away – it usually means the process starts over.
Example: During a felony assault trial, a witness mentions the defendant’s prior conviction, which the judge had ruled inadmissible. The defense attorney moves for a mistrial, arguing the jury has been prejudiced. The judge agrees and declares a mistrial. The case is scheduled for a new trial with a new jury.
Criminal and civil trials, when a serious error or event prevents a fair trial