Mistrial vs. Hung Jury: What's the Difference?

A hung jury and a mistrial are not the same thing — one is a cause of the other. A mistrial is any trial that ends without a valid verdict. A hung jury, where jurors cannot agree, is the most common reason a judge declares a mistrial, but it is not the only one. And crucially, a mistrial is not an acquittal: in most cases the prosecution is free to try the defendant again.

The Short Version

• A mistrial is a trial that ends without a verdict and is invalidated by the judge.
• A hung jury (a “deadlocked” jury) is jurors who cannot reach the required agreement — the leading cause of a mistrial, but only one cause.
• Other causes of a mistrial: a serious procedural error, prejudicial misconduct, or the death or illness of a juror or attorney.
• A mistrial is not a verdict — the defendant is neither convicted nor acquitted.
• After a mistrial from a hung jury, the defendant can usually be retried. Double jeopardy does not bar it.
• An acquittal (a unanimous “not guilty”) is final — the defendant cannot be retried for that charge.
• Exact rules vary by jurisdiction. This is the common framework, not a single national law.

In Depth

What exactly is a mistrial?

A mistrial is a trial that the judge ends before a valid verdict is reached, because something has made it impossible or unfair to continue. The trial is essentially wiped — it no longer counts. A mistrial can be declared for several reasons: a jury that cannot agree, a procedural error serious enough to prejudice one side, misconduct by an attorney, juror, or witness, or an emergency such as the death or illness of a juror or lawyer. The unifying idea is that the proceeding cannot fairly produce a verdict, so the law refuses to let a flawed one stand.

So where does the “hung jury” fit in?

A hung jury is one specific cause of a mistrial — the most common one. In a criminal trial, the verdict usually must be unanimous. When jurors are split and cannot reach that agreement no matter how long they deliberate, they are “deadlocked,” or “hung.” At that point the judge typically declares a mistrial. So every hung jury can lead to a mistrial, but not every mistrial comes from a hung jury.

What does a judge do when jurors say they’re stuck?

Before giving up, a judge will often send a deadlocked jury back to keep trying — usually once or twice. This instruction is known as an Allen charge, sometimes called a “dynamite instruction” because it is meant to blast the jury loose from its deadlock. It encourages jurors to re-examine their views and listen to one another, without abandoning their honest convictions. If the jury still cannot agree after that, the judge declares the mistrial.

Can the defendant be tried again?

Usually, yes. Because a mistrial produces no verdict, the protection against double jeopardy — being tried twice for the same offense — generally does not apply when the mistrial results from a hung jury or is requested or consented to by the defense. The prosecution then decides whether to retry the case, pursue a plea, or drop the remaining charges. This is very different from an acquittal: a unanimous “not guilty” is a final verdict, and the Constitution bars retrying a defendant on that charge. A mistrial leaves the question open; an acquittal closes it for good.

Is there a real example of how this plays out?

Yes — and a recent, high-profile one. In the case of Karen Read, her first trial ended in a mistrial after the jury deadlocked. Because a hung-jury mistrial is not an acquittal, prosecutors were free to try her again — and they did, at a second trial that reached a verdict. The arc shows the whole sequence in practice: deadlock, mistrial, retrial, and finally a binding verdict that double jeopardy then makes permanent.

Does this differ by location?

Yes. Whether a verdict must be unanimous, how many times a judge may issue an Allen charge, and how courts handle the timing of a mistrial all vary by jurisdiction and have evolved through court decisions. What holds nearly everywhere is the core distinction: a hung jury is a reason for a mistrial, a mistrial is not a verdict, and only an acquittal ends the matter for good.