What is a Mistrial?
A mistrial, in law, an erroneous or invalid trial, or a case in which the jury is discharged without having reached a verdict. In legal effect, it is equivalent to no trial at all. A mistrial is declared because of some circumstance indicating that justice may not be done if the trial continues. It may be granted only as a result of a fundamental error or shortcoming vitiating the whole proceedings rather than merely for an erroneous ruling on a point of law. Since a mistrial is a failure of trial, it is not a judgment or order in favor of one of the parties.
In a civil proceeding, a mistrial may be declared when necessary to further justice as, for example, in cases of surprise, an unexpected act. A mistrial may also be granted because of improper remarks or conduct of counsel, misconduct of jurors, introduction of improper evidence, or emotional demonstration by a litigant. In criminal cases, the prevailing view is that the court may declare a mistrial when necessity or the ends of public justice require it, even without the consent of the accused. A trial judge has broad, but not absolute, discretion in determining whether or not to declare a mistrial.