What Is a Mistrial Motion: Ending a Trial Without a Verdict

What a Mistrial Motion Is

A mistrial motion is a request asking the court to end a trial without a verdict because something has gone seriously wrong. A trial is built to reach a result, a verdict from the fact-finder, but sometimes an event during the trial is serious enough that continuing would not be fair, or the jury simply cannot agree. When that happens, a party can ask the judge to declare a mistrial, stopping the proceeding before it reaches the verdict it was meant to produce.

The word can be confusing because a mistrial is not an acquittal and not a conviction. It is the trial being called off partway through. Either side can sometimes raise it, and in some situations the judge can declare one without either side asking. What follows afterward depends on why the mistrial happened and on the rules of the jurisdiction.

Common Reasons a Mistrial Is Raised

Mistrials are not routine; the bar is generally high, because courts prefer to let a trial finish. But several recurring situations come up:

• A deadlocked jury. When jurors cannot reach the required agreement after genuine effort, sometimes called a hung jury, the judge may declare a mistrial.
• A significant error or improper evidence. When the jury hears something it should not have, and the harm cannot be undone by telling them to disregard it, a party may argue the trial can no longer be fair.
• Misconduct. Serious misconduct by a participant, a witness, or even a juror can undermine the proceeding enough to support the request.
• An emergency or breakdown. Events that make it impossible to continue fairly, such as the loss of too many jurors, can lead a court to stop the trial.

Not every error supports a mistrial. Many problems are handled by a judge instructing the jury to disregard something, and a mistrial is generally reserved for situations a lesser fix cannot cure.

How the Request Gets Decided

When a mistrial is requested, the judge weighs whether the problem is serious enough that the trial cannot fairly go on, and whether a smaller remedy would be enough instead. A lawyer raising the motion is usually arguing that the harm cannot be undone; the other side may argue that the trial can continue, sometimes with a corrective instruction. The judge then rules.

Timing matters. The motion is often made the moment the problem surfaces, because raising an issue promptly can be part of preserving it. Whether and how a mistrial can be sought, and what the judge must consider, varies by jurisdiction, which is why two courts can handle similar situations differently.

What Can Follow a Mistrial

A mistrial ends the current trial, not necessarily the case. In many situations the prosecution may seek to try the matter again before a new jury, so a mistrial can mean a reset rather than an end. In other situations, the parties may reassess and the case may resolve a different way, and the path forward depends heavily on the reason for the mistrial.

One important wrinkle worth knowing about, though the rules are jurisdiction-specific and fact-specific, is that the reason for a mistrial can sometimes affect whether a retrial is even allowed. Certain mistrials, particularly some caused by the prosecution, may raise questions about being tried twice for the same offense. Where that line falls is a detailed legal question that turns on exactly what happened and where.

Where It Fits in a Trial

A mistrial motion is one of several things that can happen once a trial is underway, alongside the judge instructing the jury and the jury deliberating toward a verdict. Seeing it as one possible branch, the trial stops and resets rather than finishing, can make a confusing moment less alarming. The what-a-criminal-trial-looks-like guide places this branch inside the full sequence of a trial.

A defendant who hears “we moved for a mistrial” is hearing that the defense believes something went seriously enough wrong that the trial should not continue as it stands, not that the case is over.

Questions to Explore

For someone trying to understand a mistrial in their case, these are questions many defendants raise with counsel:

1. What specifically went wrong, and why does it rise to the level of a mistrial here?
2. Was a smaller remedy, like a corrective instruction, available instead?
3. If a mistrial is declared, can the case be tried again in this situation?
4. Does the reason for the mistrial affect whether a retrial is allowed?
5. What are the realistic next steps if the trial is stopped this way?