Mistrial Meaning: What Does “Mistrial” Mean?

What Does “Mistrial” Mean?

Cornell Law’s Legal Information Institute defines it: “A mistrial occurs when a trial cannot fairly or properly proceed to a verdict.” The judge terminates the trial — and the proceedings are treated as void, “as though they never occurred.”

The critical point: a mistrial is not a decision. Nobody won; nobody was cleared. The legal slate is wiped — and the case typically starts over.

Mistrials can be declared in both criminal and civil trials, at any point before the verdict — during jury selection, testimony, deliberation, or even mid-sentence of a closing argument.

Common Causes of Mistrials

• Hung jury (most common): the jurors cannot reach the required verdict — deadlocked after extensive deliberation. The judge first issues an Allen charge (“keep trying”) — if that fails, mistrial.
• Juror misconduct: a juror researches the case online, discusses it with outsiders, lies during selection, or is contacted by a party. Any taint of bias can void the trial.
• Attorney misconduct: improper statements to the jury, withholding evidence (Brady violations), coaching witnesses, or deliberately provoking a mistrial (which can bar retrial — see below).
• Procedural errors: wrongly admitted evidence, incorrect jury instructions, biased rulings — errors so serious the trial can’t be fairly completed.
• Emergencies: death or illness of the judge, an attorney, or a juror; natural disasters; courtroom disruptions that make proceeding impossible.
• Defendant’s actions: if the defendant becomes disruptive or incompetent mid-trial, the judge may declare a mistrial.

What Happens After a Mistrial?

• The trial is void: legally, it’s “as though it never occurred” — the evidence presented, the testimony heard, all erased from the record.
• Retrial is the norm: the prosecution (or plaintiff) can start over — new jury, same charges. The defendant is typically released on bail (or held) pending retrial.
• Strategic reset: both sides learn from the mistrial — witnesses revealed, strategies exposed. The retrial is rarely a replay.
• Plea bargaining: many mistrials lead to plea deals — the uncertainty of retrial pushes both sides to settle.
• Dismissal (rare): the prosecution may drop the case — if witnesses are unavailable, evidence weakened, or the cost isn’t justified.

Double Jeopardy & Mistrials

The Fifth Amendment protects against double jeopardy (being tried twice for the same crime) — but mistrials are the major exception:

• The general rule: if the defendant requests the mistrial (or consents to it), retrial is allowed — the defendant waived the protection.
• Hung jury: always retriable — the Supreme Court has consistently held that a deadlocked jury is “manifest necessity” for mistrial.
• The exception: if the prosecution deliberately provoked the mistrial (e.g., goading the defense into requesting one to get a second chance), double jeopardy bars retrial. (Oregon v. Kennedy, 1982.)
• Prosecutorial misconduct: if misconduct (hidden evidence, witness tampering) forced the mistrial, courts may bar retrial as a sanction.
• The principle: the state gets one fair shot — not unlimited shots. Deliberate sabotage forfeits the retrial.

Mistrial vs Related Legal Terms

Term	What Happens	Can They Retry?
Mistrial	Trial voided before verdict	Usually yes
Acquittal	Found not guilty — final	No (double jeopardy)
Dismissal	Case thrown out (often pre-trial)	Sometimes (depends on “with/without prejudice”)
Hung jury	Jury deadlocked	Yes — it causes a mistrial
New trial	Completed trial set aside, redone	Yes — it’s a do-over
Nolle prosequi	Prosecution drops charges	Usually yes (unless jeopardy attached)

The key confusion: people hear “mistrial” and think “got off.” Wrong — a mistrial means “no decision.” An acquittal means “not guilty.” Very different.

Famous Mistrials

• Bill Cosby (2017): first trial ended in a hung jury → mistrial. Retried in 2018 → convicted. (Conviction later overturned on procedural grounds.)
• O.J. Simpson (civil): the criminal trial (1995) was an acquittal, not a mistrial — but the distinction is commonly confused.
• Menendez brothers (1994): first trials ended in hung juries → mistrials. Retried → convicted.
• The pattern: high-profile mistrials almost always lead to retrial — the stakes are too high to drop.

Mistrials in Civil Cases

• Same concept: a civil trial can be voided before verdict for the same reasons — hung jury, misconduct, error.
• No double jeopardy: the Fifth Amendment protection applies to criminal cases — civil retrials face fewer barriers.
• Common in: personal injury, medical malpractice, product liability — wherever juries decide complex facts.
• Settlement pressure: a civil mistrial often accelerates settlement — both sides have seen the other’s case and want to avoid the cost of redoing it.

How a Mistrial Is Declared

• Who can request: either party (prosecution/plaintiff or defense) — or the judge can act sua sponte (on their own initiative).
• The motion: the requesting party files a motion for mistrial — arguing the trial cannot fairly proceed. The judge decides.
• The standard: “manifest necessity” — the judge must find a compelling reason. Not every error qualifies — minor issues get curative instructions (“disregard that statement”) instead.
• Alternatives first: judges prefer to save the trial — striking testimony, instructing the jury, replacing a juror with an alternate. Mistrial is the last resort.
• The declaration: the judge discharges the jury, declares the mistrial on the record, and sets a retrial date (or schedules a hearing on next steps).
• Strategic timing: a party might want a mistrial (if the trial is going badly) or oppose it (if winning). The judge sees through tactical requests.

Preventing Mistrials

• Jury instructions: clear, repeated admonitions — don’t research, don’t discuss, don’t read news. Written instructions help.
• Sequestration: in high-profile cases, juries may be sequestered (isolated in hotels) — extreme but effective.
• Voir dire rigor: thorough jury selection — screening for bias, hardship, and hidden agendas.
• Alternate jurors: seating alternates allows replacement without mistrial if a juror is lost.
• Attorney discipline: judges warn attorneys against improper conduct — the threat of sanctions deters deliberate sabotage.

The Bottom Line

A mistrial is the legal system’s reset button:

• Not an acquittal, not a conviction — a void
• Most common cause: hung jury
• Usual outcome: retrial
• Double jeopardy rarely bars it — unless the prosecution cheated

Remember: “mistrial” ≠  “got away with it.” It means “we’ll do this again.”

Mistrial Quick Facts

Fact	Detail
Definition	Trial voided before verdict
Most common cause	Hung jury
Usual outcome	Retrial
Double jeopardy	Rarely bars retrial
Applies to	Criminal and civil cases

Pro tip: if you’re following a high-profile case, “mistrial” in headlines means “no verdict yet” — not “the defendant walked.”

One more thing: judges hate declaring mistrials — it’s expensive, time-consuming, and frustrating for everyone. When it happens, the reason was serious.

Frequently Asked Questions

What does “mistrial” mean?
A trial terminated before a verdict — declared void, as if it never happened.

Does the defendant go free after a mistrial?
Not automatically. The usual outcome is a retrial — the defendant is not cleared.

What’s the difference between a mistrial and an acquittal?
Acquittal = found not guilty (final, can’t retry). Mistrial = no decision (usually can retry).

Can you be retried after a mistrial?
Usually yes — unless prosecutorial misconduct deliberately caused the mistrial (double jeopardy then bars retrial).

What is a hung jury?
A jury that cannot agree on a verdict after thorough deliberation — the most common cause of mistrials.

Who declares a mistrial?
The judge — either on request (by either party) or sua sponte (on the judge’s own initiative).

Can a mistrial happen in a civil case?
Yes — same concept, same causes. Double jeopardy doesn’t apply to civil retrials.

How do you use “mistrial” in a sentence?
“The case ended in a mistrial after the jury deadlocked.”

How common are mistrials?
Relatively rare — estimates suggest ~6-8% of criminal jury trials end in hung juries. Most trials reach a verdict.

Can the judge declare a mistrial over someone’s objection?
Yes — the judge has inherent authority. But if the defendant objects and the judge declares it anyway (without manifest necessity), double jeopardy may bar retrial.

What happens to the jury after a mistrial?
They’re discharged — sent home with thanks. They cannot serve on the retrial.

Related legal terms on SpellProf: clemency meaning, persona non grata meaning.

Source: For the legal definition, see Cornell LII’s entry for mistrial.