A mistrial means a trial has ended before the jury or judge reached a verdict, wiping the slate as if the trial never happened. No conviction, no acquittal. The charges remain, the case stays open, and the prosecution decides whether to try again, offer a plea, or drop it. Judges treat a mistrial as a last resort, used only when something has gone so wrong that no instruction or correction can rescue a fair outcome.
Why Mistrials Are Declared
Mistrials come from a short list of recurring problems, all rooted in the same idea: the trial’s fairness has been compromised beyond repair.
The most common cause is a hung jury. After the Supreme Court’s 2020 decision in Ramos v. Louisiana, every state and federal criminal case requires a unanimous jury.1Supreme Court of the United States. Ramos v. Louisiana When deliberations hit a genuine impasse, the judge discharges the jury and declares a mistrial.
Tainted evidence is another trigger. If jurors hear something they were never supposed to consider, like a defendant’s prior convictions introduced in violation of the rules of evidence, the damage may be irreversible. Federal Rule of Evidence 609 limits when prior convictions can be used and requires judges to weigh their prejudicial effect.2Legal Information Institute. Federal Rule of Evidence 609 – Impeachment by Evidence of a Criminal Conviction When excluded evidence slips through, the judge has to decide whether an instruction to disregard can realistically fix the problem or whether the jury’s impartiality is gone.
Juror misconduct can end a trial too. Jurors are supposed to decide the case only on what is presented in the courtroom. Independent internet research, looking up the defendant on social media, visiting the scene, or communicating with anyone involved all violate that duty, and these problems have become more common in the smartphone era.
Attorney misconduct is a separate category. Prosecutors or defense lawyers can poison a trial through inflammatory closing remarks, referencing evidence the judge excluded, or violating a defendant’s constitutional rights during cross-examination. The Rittenhouse murder trial nearly ended in a mistrial after the prosecutor referenced excluded evidence and questioned the defendant about his pre-trial silence.
Finally, unforeseen events can leave the court no choice. The death or serious illness of the judge, a juror, or a lead attorney is rare, but it can make continuing physically impossible.
Before declaring a mistrial, judges usually try smaller fixes first: a curative instruction telling the jury to disregard what it just heard, or an order striking testimony from the record. Courts generally presume jurors follow those instructions, and an isolated slip can often be cured that way. A mistrial comes when the problem is too serious to patch.
What Happens to the Case After a Mistrial
A mistrial resets the legal process to roughly where it stood before trial began. The charges remain pending, no verdict exists, and the prosecution has to pick a path. There are three.
Retrial
The prosecution can try the case again with a new jury. This is the most common outcome when a hung jury caused the mistrial. In federal court, the Speedy Trial Act requires the retrial to begin within 70 days after the mistrial order becomes final, though various procedural delays are excluded from that clock.3Office of the Law Revision Counsel. 18 USC 3161 – Time Limits and Exclusions State deadlines vary but follow a similar logic.
A retrial is not a carbon copy of the first. Both sides learn. The prosecution may tighten its evidence or call different witnesses. The defense now knows the prosecution’s strategy and can prepare accordingly. The real cost of a mistrial shows up here: the defendant endures the expense and anxiety of a second trial, and the public pays for additional prosecution resources.
Plea Bargain
If a hung jury signals weaknesses in the prosecution’s case, both sides have reason to negotiate. The prosecution may offer a reduced charge or lighter sentence recommendation rather than risk another deadlock. For the defendant, a plea provides certainty and avoids a second trial. Many cases resolve this way after a mistrial, especially when the jury split heavily toward acquittal.
Dismissal
The prosecution can also drop the case entirely. That happens when a retrial seems unlikely to produce a different result, when key evidence has weakened, or when a critical witness is no longer available. A dismissal after a mistrial is typically without prejudice, meaning the charges could theoretically be refiled, though speedy trial rules and practical constraints often prevent that.
Your Status in the Meantime
A mistrial does not automatically release a defendant from custody or change bail conditions. If you were out on bail before the mistrial, those conditions generally continue. If you were in custody, you stay there unless the court modifies the arrangement. Judges have discretion to adjust bail after a mistrial, and you can request a hearing to argue that changed circumstances justify release or a lower amount. The gap between a mistrial and resolution can stretch for months, and the defendant carries that uncertainty.
Can You Be Tried Again After a Mistrial
The Fifth Amendment protects against being prosecuted twice for the same offense.4Library of Congress. Overview of Double Jeopardy Clause At first glance, a retrial after a mistrial looks like a violation. In most situations it is not, but the analysis depends on how the mistrial happened.
Jeopardy attaches when the jury is empaneled and sworn, or in a bench trial when the first witness begins testifying. Before that point, the prosecution can dismiss and refile without any double jeopardy problem. After it, the question is whether ending the trial bars a second one.
Because a mistrial ends the case without a verdict, courts treat the retrial as a continuation of the original jeopardy rather than a second prosecution. A hung jury is the clearest example: the jury could not agree, and the prosecution is free to try again.5Congress.gov. Constitution Annotated – Amdt5.3.4 Re-Prosecution After Mistrial
The Manifest Necessity Rule
When a judge declares a mistrial over the defendant’s objection, the law demands more than inconvenience. The standard, set by the Supreme Court in United States v. Perez in 1824, is called manifest necessity. A judge may discharge a jury without barring retrial when there is a manifest necessity for doing so, or when the ends of public justice would otherwise be defeated. The Court added that the power “ought to be used with the greatest caution, under urgent circumstances, and for very plain and obvious causes.”6Justia. United States v. Perez A hung jury clears that bar easily. A prosecutor’s fumble that the judge could have fixed with an instruction does not.7Legal Information Institute. Re-Prosecution After Mistrial
When You Asked for the Mistrial
If the defendant moves for a mistrial and the court grants it, the defendant generally cannot then claim double jeopardy blocks a retrial. The logic: you asked for the do-over, so you accepted a second trial.
There is one narrow exception. In Oregon v. Kennedy (1982), the Supreme Court held that if the prosecution deliberately provoked the defendant into requesting a mistrial, double jeopardy bars a retrial. The government’s conduct must have been “intended to ‘goad’ the defendant into moving for a mistrial.”8Justia. Oregon v. Kennedy Recklessness or incompetence is not enough; the defendant must show the prosecutor wanted the mistrial as a tactical move. The standard is hard to meet, and courts read Kennedy narrowly. Some states offer broader protection under their own constitutions, barring retrial when prosecutorial misconduct is egregious enough to be fundamentally unfair even without proof of specific intent.7Legal Information Institute. Re-Prosecution After Mistrial
Mistrials in Civil Cases
Everything above concerns criminal trials. Mistrials happen in civil cases too, with similar mechanics: a jury deadlock, juror misconduct, or tainted evidence can force a new trial. Federal Rule of Civil Procedure 48 requires a unanimous verdict from at least six jurors in federal civil cases unless both parties agree otherwise.9Legal Information Institute. Federal Rules of Civil Procedure Rule 48 – Number of Jurors, Verdict, Polling
The important difference is that double jeopardy does not apply. The Fifth Amendment’s protection is limited to criminal prosecutions, so either party in a civil case can be retried without constitutional barriers. The constraints are practical: the cost of a second trial, witness availability, and whether a settlement makes more sense than another throw of the dice. Civil mistrials often push the parties toward settlement rather than retrial.