Arizona v. Washington

The Double Jeopardy Clause protects not only against a second trial after an acquittal, but also against the unnecessary termination of a trial after jeopardy has attached. A defendant has a valued right to have the first jury decide the case because a second prosecution brings added expense, anxiety, stigma, and a greater risk of an erroneous conviction. When the defendant objects to a mistrial, the prosecution bears a heavy burden to show “manifest necessity.”

Manifest necessity is not a mechanical or literal test. It requires a high degree of need, assessed in light of the particular trial problem. The Court distinguished cases where the prosecution seeks a mistrial to repair weaknesses in its evidence or gain a tactical advantage, which demand the strictest scrutiny, from situations such as a genuinely deadlocked jury, where the trial judge receives substantial deference.

A mistrial based on possible juror bias from improper argument falls in an area warranting special respect for the trial judge's judgment. The trial judge heard the argument as delivered, observed the jurors, knew the case's context, and was better positioned than an appellate court to assess whether the remarks had affected the impartiality of one or more jurors. Although a cautionary instruction might have sufficed in another judge's view, the Constitution does not require an appellate court to substitute its own assessment for the trial judge's informed evaluation.

For purposes of its analysis, the Court accepted that defense counsel's remarks were improper under Arizona law. Counsel had told the jury that the prior prosecutor deliberately withheld evidence and that the Arizona Supreme Court granted a new trial for that reason, even though counsel could not identify a valid basis for admitting that information at the new trial. Such remarks could taint the entire jury by inviting it to judge the prosecution for alleged prior misconduct rather than decide the defendant's guilt on admissible evidence.

The record showed that the judge acted deliberately rather than precipitately. He initially denied the mistrial motion, permitted further research and argument, heard both sides on the seriousness of the prejudice and the possible use of curative instructions, and expressly recognized that an erroneous mistrial ruling could bar retrial. The Court therefore concluded that he exercised sound discretion and that the public interest in an impartial trial and a just judgment outweighed the defendant's interest in continuing before the first jury.

Express findings and a full explanation are desirable because they make appellate review easier. But the Double Jeopardy Clause does not make a mistrial order constitutionally defective merely because the judge did not utter the phrase “manifest necessity” or separately list every alternative considered.

The surrounding record adequately revealed the ruling's basis: defense counsel had injected inadmissible and potentially prejudicial claims of prosecutorial misconduct into the trial; the parties argued whether the prejudice could be cured without a mistrial; and the judge showed awareness of the serious double-jeopardy consequences of aborting the proceedings. A reviewing court could therefore determine that the judge acted responsibly and deliberately.

The lower courts gave excessive weight to the form of the ruling. They improperly treated the absence of express findings as a reason to infer that the trial judge had failed to consider jury impartiality or the governing constitutional standard. A federal habeas court may not invalidate a state mistrial declaration solely because the state judge did not articulate his reasoning in particular words.