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A courtroom trial that has been terminated prior to its normal conclusion. A mistrial has no legal effect and is considered an invalid or nugatory trial. It differs from a "new trial," which recognizes that a trial was completed but was set aside so that the issues could be tried again.

A judge may declare a mistrial for several reasons, including lack of jurisdiction, incorrect jury selection, or a deadlocked, or hung, jury. A deadlocked jury—where the jurors cannot agree over the defendant's guilt or innocence—is a common reason for declaring a mistrial. Extraordinary circumstances, such as death or illness of a necessary juror or an attorney, may also result in a mistrial. A mistrial may also result from a fundamental error so prejudicial to the defendant that it cannot be cured by appropriate instructions to the jury, such as improper remarks made during the prosecution's summation.

In determining whether to declare a mistrial, the court must decide whether the error is so prejudicial and fundamental that expenditure of further time and expense would be wasteful, if not futile. Although the judge has the power to declare a mistrial and discharge a jury, this power should be "exercised with great care and only in cases of absolute necessity" (Salvatore v. State of Florida, 366 So. 2d 745 [Fla. 1978], cert. denied, 444 U.S. 885, 100 S. Ct. 177, 62 L. Ed. 2d 115 [1979]).

For example, in Ferguson v. State, 417 So. 2d 639 (Fla. 1982), the defendant moved for a mistrial because of an allegedly improper comment made by the prosecution during closing argument. The prosecution stated that not only was defense counsel asking the jury to find a scapegoat for the defendant's guilt, he was also putting the blame on someone who had already been found guilty. The appellate court found that the lower court had properly denied the motion for a mistrial because the prosecutor's comment fell within the bounds of "fair reply."

A mistrial in a criminal prosecution may prevent retrial under the Double Jeopardy provision of the Fifth Amendment, which prohibits an individual from being tried twice for the same offense, unless required by the interests of justice and depending on which party moved for the mistrial. Typically, there is no bar to a retrial if the defendant requests or consents to a mistrial. A retrial may be barred if the court grants a mistrial without the defendant's consent, or over his objection. If the mistrial results from judicial or prosecutorial misconduct, a retrial will be barred. In United States v. Jorn, 400 U.S. 470, 91 S. Ct. 547, 27 L. Ed. 2d 543 (1971), the Supreme Court held that reprosecuting the defendant would constitute double jeopardy because the judge had abused his discretion in declaring a mistrial. On his own motion, the judge had declared a mistrial to enable government witnesses to consult with their own attorneys.


Criminal Procedure; Harmless Error; Hung Jury.


n. the termination of a trial before its normal conclusion because of a procedural error, statements by a witness, judge or attorney which prejudice a jury, a deadlock by a jury without reaching a verdict after lengthy deliberation (a "hung" jury), or the failure to complete a trial within the time set by the court. When such situations arise, the judge, either on his own initiative or upon the motion (request) of one of the parties will "declare a mistrial," dismiss the jury if there is one, and direct that the lawsuit or criminal prosecution be set for trial again, starting from the beginning. (See: trial)


noun abrogation, annulment, cancellation, collapse, disannulment, erroneous trial, failure, fruitless trial, innffective trial, invalid trial, nonfulfillment, nugaaory trial, nullification, nullity, revocation, terminated trial, unproductive trial, unsuccessful trial, useless trial, void trial, worthless trial
Associated concepts: deadlocked jury, declaration of a missrial, prejudicial error


a trial made void because of some error, such as a defect in procedure. In the US an inconclusive trial, as when a jury cannot agree on a verdict.

MISTRIAL. An erroneous trial on account of some defect in the persons trying, as if the jury come from the wrong county or because there was no issue formed, as if no plea be entered; or some other defect of jurisdiction. 3 Cro. 284; Hob. 5; 2 M. & S. 270.

References in periodicals archive ?
Kelly Blackburn, the assistant Montgomery County district attorney trying Reynolds' case, confirmed the mistrial and said that a new trial had been set for Jan.
Koh denied Samsung's request for a mistrial and instead called the jury back into the courtroom, where she re-read the jury instructions and reminded the jurors that they were not to be influenced by personal likes or dislikes, opinions, prejudices, or sympathy.
Larson said he believed the woman made "grossly inappropriate" statements, but he made a distinction between a civil case, like this one, and a criminal case before making his decision on the mistrial motion.
The possibility of a mistrial was raised on Tuesday after prosecutors said the judge gave flawed instructions to a jury of military officers and asked him to revise it.
In 2005, Judge Cooper declared a mistrial in the Wallace case after finding that Detective Katz hid statements linking the killing of Christopher Wallace to rogue cops David A.
In declaring a mistrial in the penalty phase, Los Angeles Superior Court Judge Robert J.
The group urges the Chinese authorities ''to release Gao, declare a mistrial in Chen's case and ensure that lawyers are free of intimidation and interference as they carry out their professional duties,'' the statement said.
Jackson's team opened their defence yesterday by filing a motion asking the judge to declare a mistrial.
The mistrial for England, a 22-year-old reservist who appeared in some of the most notorious photographs from the 2003 abuse scandal, means the case gets kicked back to the military equivalent of a grand jury proceeding.
In a major setback for victims' advocates last fall, a Rhode Island judge declared a mistrial after the jury could not agree that the paint was a public nuisance for continuing to poison the state's children (despite evidence of elevated blood lead levels in some children).
An inadvertently locked door led to a mistrial for an Alberta man.