What constitutes a mistrial in a magistrates court?

Answer 1

A judge may cancel a trial prior to the return of a verdict; legal parlance designates this as a mistrial.

A judge may declare a mistrial due to:

• The court determining that it lacks jurisdiction over a case,
• Evidence being admitted improperly,
• Misconduct by a party, juror,[1] or an outside actor, if it prevents due process,
• A hung jury which cannot reach a verdict with the required degree of unanimity
• Disqualification of a juror after the jury is impanelled, if no alternate juror is available and the litigants do not agree to proceed with the remaining jurors.

A declaration of a mistrial generally means that a court must hold a retrial on the same subject.

An important exception occurs in criminal cases in the United States. If the court erroneously declares a mistrial, or if prosecutorial misconduct forced the defendant into moving for a mistrial, the constitutional protection against double jeopardy bars any retrial