Manifest Necessity: The Standard That Decides Whether a Mistrial Bars a Retrial

Manifest necessity is the constitutional standard a judge must meet before ending a criminal trial without a verdict and allowing the defendant to be tried again. The phrase comes from United States v. Perez, 22 U.S. (9 Wheat.) 579 (1824), where the Supreme Court held that a jury may be discharged mid-trial only when "there is a manifest necessity for the act, or the ends of public justice would otherwise be defeated." If a mistrial is declared over the defendant's objection and that standard is not met, the Double Jeopardy Clause bars a second trial. If it is met, jeopardy continues and the retrial proceeds.

Most people meet the doctrine through a motion for mistrial, but manifest necessity is a separate question from whether a mistrial should be granted. It asks whether the government gets a second chance. The sections below cover the standard, the sliding scale of scrutiny courts apply, the Supreme Court cases that found necessity and the ones that did not, how hung juries fit, and what a defense lawyer must do on the record to preserve a double jeopardy claim.

What Manifest Necessity Means

Justice Story's opinion in Perez set the rule and the tone. Trial courts have the authority to discharge a jury before verdict, but the power "ought to be used with the greatest caution, under urgent circumstances, and for very plain and obvious causes." The Court refused to define the circumstances in advance and left the judgment to the "sound discretion" of the trial judge, reviewed for abuse.

Two things follow from that origin. First, manifest necessity is not a checklist. The Supreme Court said in Wade v. Hunter, 336 U.S. 684 (1949), that the rule cannot be applied mechanically, because the situations that justify ending a trial vary too widely. Second, the word "manifest" does not mean "absolute." In Arizona v. Washington, 434 U.S. 497 (1978), the Court explained that the standard requires a "high degree" of necessity, not a literal impossibility of continuing.

The doctrine only matters when the defendant did not want the mistrial. When the defendant asks for one, or consents, the analysis shifts to a different rule discussed below.

Why Double Jeopardy Makes It Matter

The Fifth Amendment provides that no person shall "be subject for the same offence to be twice put in jeopardy of life or limb." Benton v. Maryland, 395 U.S. 784 (1969), applied the clause to the states. Jeopardy attaches in a jury trial when the jury is sworn, a federal rule the states must follow under Crist v. Bretz, 437 U.S. 28 (1978). In a bench trial it attaches when the court begins to hear evidence. Before that moment a dismissal or continuance raises no double jeopardy problem, which is why Serfass v. United States, 420 U.S. 377 (1975), allowed the government to appeal a pretrial dismissal.

Once jeopardy attaches, the defendant holds what the Court calls a "valued right" to have the trial completed by the particular tribunal that was sworn to hear it. Ending the trial early strips that right, exposes the defendant to a second round of expense and anxiety, and gives the prosecution a preview of the defense. Manifest necessity is the doctrine that decides when the public interest in a verdict outweighs that right.

Civil trials are different. The Double Jeopardy Clause protects only against successive criminal prosecutions and punishments, so a civil mistrial can always be followed by a new trial. The judge's decision is reviewed for abuse of discretion, and the losing party's remedy is an appeal after final judgment, not a bar on retrial.

The Standard: A High Degree of Necessity on a Sliding Scale

Arizona v. Washington is the modern statement of the rule. Defense counsel there told the jury in opening that the prosecution had hidden evidence in the defendant's first trial. The judge declared a mistrial over the defendant's objection without stating findings, and the defendant argued the retrial was barred. The Supreme Court upheld the retrial and, in the process, described how strictly a reviewing court should examine the mistrial ruling depending on why it was made.

Strictest scrutiny: prosecution problems

When the reason for the mistrial is that the prosecution's evidence is weak, a witness is missing, or the government is otherwise unprepared, the reviewing court applies the "strictest scrutiny." The concern is obvious. A mistrial on those grounds lets the prosecution rescue a losing case and try it again with better preparation, which is exactly what the clause forbids.

Great deference: jury bias and deadlock

When the reason is possible juror bias, improper argument that may have tainted the panel, or a jury that cannot agree, the trial judge is "in the best position" to assess the situation and the reviewing court gives the ruling "great deference." That deference is why Washington came out the way it did. The trial judge saw the improper opening, heard the arguments, and was entitled to conclude that no instruction would erase the prejudice.

What the record must show

Washington held that the judge need not recite the words "manifest necessity" or make explicit findings, as long as the record shows the basis for the ruling and that the judge exercised sound discretion rather than acting "irrationally or irresponsibly." Courts examine whether the judge heard from both sides, whether alternatives such as a curative instruction, a short continuance, or excusing a single juror were considered, and whether the judge acted precipitately. Federal Rule of Criminal Procedure 26.3 codifies the process: before ordering a mistrial, the court must give each defendant and the government an opportunity to comment on the propriety of the order, to state whether they consent or object, and to suggest alternatives.

Manifest Necessity Examples: Cases That Found It

Case	Reason for the mistrial	Result
United States v. Perez, 22 U.S. 579 (1824)	Jury could not agree in a capital case	Retrial permitted; the origin of the phrase
Wade v. Hunter, 336 U.S. 684 (1949)	Court-martial in Germany dissolved when the army advanced and witnesses became unreachable	Retrial permitted; military exigency was a necessity
Gori v. United States, 367 U.S. 364 (1961)	Judge declared a mistrial on his own motion to protect the defendant from prejudicial testimony	Retrial permitted; ruling made in the defendant's interest
Illinois v. Somerville, 410 U.S. 458 (1973)	Indictment was fatally defective under state law and any conviction would be reversed	Retrial permitted; continuing would have wasted the trial
Arizona v. Washington, 434 U.S. 497 (1978)	Defense opening statement told the jury about suppressed evidence from the first trial	Retrial permitted; deference to the judge's bias assessment
Richardson v. United States, 468 U.S. 317 (1984)	Hung jury on two counts	Retrial permitted; a hung jury does not terminate jeopardy at all
Renico v. Lett, 559 U.S. 766 (2010)	Jury reported disagreement after about four hours; judge declared a mistrial without an Allen charge	Retrial permitted; state court's ruling was not unreasonable under federal habeas review
Blueford v. Arkansas, 566 U.S. 599 (2012)	Forewoman reported the jury had voted unanimously against the two most serious charges but deadlocked on a lesser one	Retrial permitted on all charges; the report was not a final acquittal

The pattern is consistent. Where the trigger is something outside the prosecution's control, and the judge weighed the situation before acting, the Supreme Court has found necessity even when it disagreed with the wisdom of the ruling.

Cases That Found No Manifest Necessity

Downum v. United States, 372 U.S. 734 (1963). The jury was sworn, and the prosecutor then announced that a key witness had not been served with a subpoena and asked to discharge the jury. The judge agreed over the defendant's objection. The Supreme Court barred the retrial. The government had taken the chance of empaneling a jury without knowing whether its witness would appear, and it could not shift the cost of that gamble to the defendant.

United States v. Jorn, 400 U.S. 470 (1971). During a tax fraud trial the judge became concerned that prosecution witnesses had not been warned of their own exposure, and he discharged the jury on his own motion so they could consult lawyers, without asking the parties for alternatives or considering a short recess. The plurality held that the judge had acted precipitately and that the retrial was barred. Jorn is the case most often cited for the proposition that a sua sponte mistrial without a hearing on alternatives fails the standard.

The two cases mark the boundary. A prosecutor's unpreparedness and a judge's haste are the classic failures. Juror problems, deadlock, and defense misconduct are the classic successes.

Who Asked for the Mistrial Changes Everything

Manifest necessity governs mistrials declared over the defendant's objection or without the defendant's consent. When the defendant moves for the mistrial, a different rule applies.

United States v. Dinitz, 424 U.S. 600 (1976), held that a defendant who successfully moves for a mistrial ordinarily may be retried, because the defendant chose to abandon the first tribunal. Oregon v. Kennedy, 456 U.S. 667 (1982), narrowed the exception to a single question: retrial is barred only if the prosecutor's conduct that provoked the motion was intended to goad the defendant into requesting a mistrial. Prosecutorial error, overreaching, or even bad faith that falls short of that specific intent does not bar retrial. The Kennedy intent test is difficult to satisfy, which is why defense lawyers weigh carefully before moving for a mistrial in a case the prosecution appears to be losing.

A defendant who stays silent when the judge proposes a mistrial risks a finding of implied consent in some circuits, which is why the objection must be stated on the record. Consent, express or implied, removes the manifest necessity question entirely.

Hung Juries: The Prototypical Example

Arizona v. Washington called the deadlocked jury the "prototypical example" of manifest necessity, and Richardson v. United States went further, holding that a hung jury is not an event that terminates jeopardy in the first place. The practical questions in hung jury cases are about timing and procedure rather than the doctrine itself.

How long must the jury deliberate? There is no fixed minimum. In Renico v. Lett the Michigan jury had deliberated roughly four hours, sent notes suggesting conflict, and the foreperson answered "no" when asked whether the jury would reach a unanimous verdict. The Supreme Court held that the state courts' approval of the mistrial was not objectively unreasonable, while acknowledging that the trial judge could have been more thorough. The lesson for trial judges is to make a record: ask the foreperson, consider a supplemental instruction, and state why further deliberation would be futile.

Must the judge give an Allen charge first? The supplemental "dynamite" instruction approved in Allen v. United States, 164 U.S. 492 (1896), urging jurors to reconsider their positions, is a common alternative to a mistrial, but the Constitution does not require it before a deadlock mistrial. Its absence is one factor in whether the judge considered alternatives.

Partial verdicts. Federal Rule of Criminal Procedure 31(b)(3) lets the jury return a verdict on the counts it has agreed on and allows a mistrial only on the rest. A defendant facing a deadlock on one count and a likely acquittal on others should ask for a partial verdict before the jury is discharged. Blueford shows the cost of not doing so: an informal report of a unanimous vote against the top charges was not an acquittal, and the defendant could be retried on everything.

How to Preserve and Argue a Manifest Necessity Claim

1. Object on the record before the jury is discharged. State clearly that the defendant objects to the mistrial and wants the trial to continue. Silence risks implied consent.
2. Propose alternatives. A curative instruction, a brief continuance, excusing a single juror and seating an alternate, a partial verdict, or an Allen charge. Rule 26.3 entitles the defense to make those suggestions, and a judge who ignores them without explanation is closer to Jorn than to Washington.
3. Force the reasons onto the record. Ask the judge to state the basis for the mistrial. If the judge declines, put the defense understanding of the reason on the record, because the reviewing court will examine it.
4. Move to dismiss before the retrial. The double jeopardy claim is raised by a motion to dismiss the second prosecution. Under Abney v. United States, 431 U.S. 651 (1977), the denial of a double jeopardy motion is immediately appealable as a collateral order, so the defendant does not have to sit through the second trial to test the ruling.
5. Frame the scrutiny level. If the mistrial rescued a faltering prosecution, argue that Washington requires the strictest scrutiny. If the government argues jury bias, examine whether the judge actually assessed the panel or simply reacted.

The same record matters if the case instead ends in a verdict and heads to a motion for new trial or a notice of appeal. Trial errors that did not justify a mistrial can still support post-trial relief.

Manifest Necessity in State Courts

Because the doctrine is part of the Fifth Amendment as applied through the Fourteenth, every state court must apply at least the Perez standard when a mistrial is declared over objection. States may add protections. California, for example, permits discharge of a deadlocked jury only when "it satisfactorily appears that there is no reasonable probability that the jury can agree" (Cal. Penal Code section 1140), and California courts treat a discharge without that finding as a bar to retrial. Several states require the judge to make express findings, and some hold that an unnecessary mistrial bars retrial under the state constitution even where the federal rule might not. A defense lawyer should check both the state double jeopardy provision and the state's mistrial rule before the retrial is scheduled.

Manifest Necessity and Trial Strategy

The doctrine shapes decisions long before a jury deadlocks. Prosecutors who know a witness is unreliable secure a continuance before the jury is sworn, because Downum makes the alternative fatal. Defense lawyers who see a prosecution collapsing avoid moving for a mistrial, because Kennedy makes a retrial nearly certain once they do. Judges who suspect a juror problem hold a hearing and consider substitutes before discharging the panel, because Jorn punishes haste. And every party polices the opening statement and closing argument for the kind of remark that gave Arizona v. Washington its facts. Rulings on a motion in limine exist partly to keep those remarks from ever reaching the jury.

Frequently Asked Questions

What is manifest necessity in simple terms?

It is the legal justification a judge needs to end a criminal trial early, over the defendant's objection, and still allow the government to try the defendant again. Without it, the Double Jeopardy Clause bars a second trial.

Is a hung jury manifest necessity?

Yes. A genuinely deadlocked jury is the classic example, and the Supreme Court has held that a hung jury does not even end jeopardy. The disputes in hung jury cases are about whether the jury was really deadlocked and whether the judge considered alternatives first.

Can you be retried after a mistrial?

Usually. Retrial is permitted when the defendant requested or consented to the mistrial, unless the prosecutor deliberately provoked the request, and when a mistrial over objection was supported by manifest necessity. Retrial is barred when a mistrial over objection lacked that necessity, as in Downum and Jorn.

Does manifest necessity apply in civil cases?

No. Double jeopardy applies only to criminal prosecutions. A civil mistrial is reviewed for abuse of discretion and is always followed by the possibility of a new trial.

Who decides whether manifest necessity existed?

The trial judge makes the initial ruling. If the defendant moves to dismiss the retrial on double jeopardy grounds and loses, the defendant can appeal immediately, and the appellate court reviews the mistrial ruling for abuse of discretion, applying stricter scrutiny when the mistrial helped the prosecution.

What happens if a court later finds there was no manifest necessity?

The second prosecution is dismissed. Because jeopardy attached in the first trial and was terminated without necessity, the defendant cannot be tried again for that offense. The dismissal is with prejudice.

What does manifest necessity have to do with double jeopardy?

They are two halves of one rule. Double jeopardy forbids a second trial after jeopardy attaches. Manifest necessity is the exception that lets a trial end without a verdict and start over. Whether the exception applies is the whole fight.