What Happens in a Mistrial? A Criminal Defense Attorney Explains


What happens in a mistrial is the judge calls off the trial because something happened that invalidates it. For example, the state’s attorney may have made unethical comments about the accused to the jury. The government can still decide to continue the case after the mistrial; however, this doesn’t always happen. In most situations, having a new trial after a mistrial isn’t unconstitutional because you didn’t finish the first trial. 

The attorneys at Martin & Reed, LLC, have been fighting for the rights of the accused in Colorado for a combined over 30 years. Our Colorado criminal defense attorneys have handled over 100 jury trials. One of our founding attorneys, Bradley Martin, is a former public defender who has handled thousands of cases ranging from minor misdemeanors to first-degree murder. 

What Exactly Is a Mistrial?

A mistrial is where a judge in a criminal case stops the trial because of a serious error. Typically, the mistake should be so apparent and wrong that it invalidates the fairness of the trial. In other words, the whole purpose of the trial—e.g., the administration of justice—should be threatened because of this error. 

The judge can call a mistrial because someone requested it—such as the defense attorney or prosecutor. Additionally, a judge can declare a mistrial if they independently see something that they think invalidates the trial. 

What Are the Grounds for a Mistrial?

Colorado law doesn’t have a restrictive list of reasons a mistrial may be called. Instead, the underlying question is whether something happened that might make the trial’s end result unfair. A wide range of conduct might fall under this umbrella, from attorney misconduct to a hung jury or the judge making an inappropriate comment. 

If you are facing criminal charges in Colorado—such as a crime of violence—you deserve a defense attorney who has your back every step of the way. The lawyer can keep a careful watch over the activity in the courtroom to make sure nothing happens that unfairly prejudices you. If something occurs—like the judge giving the jury incorrect instructions—your attorney can take steps to limit the consequences and, if necessary, ask for the judge to declare a mistrial. 

Attorney Misconduct

Both attorneys—the prosecutor and the defense lawyer—are responsible for acting ethically and responsibly throughout the case. Even though they are on opposite sides of the case, they need to treat each other, the legal process, the accused, and others with respect. 

When either attorney fails to act ethically, it may unfairly prejudice the accused. An example is if one of the lawyers makes crude or insulting comments about the defense attorney, the accused, or others involved in the case. In that situation, someone—such as the accused or the judge—may use this as grounds to declare a mistrial. 

Hung Jury

Under Colorado law, all 12 members of the jury need to agree on the outcome of the criminal case. If even one of the jurors disagrees with the other 11 jurors’ decision, the accused cannot be found guilty or non-guilty of the crime in question. When this is used as a basis for a mistrial, the accused is neither guilty nor not guilty, and the trial can continue later on. So, if there is a mistrial in someone’s homicide case, the prosecution may decide to initiate a new trial in the future. 

The Judge Makes a Serious Mistake

The judge is responsible for being a neutral overseer of the criminal case, guiding the proceedings, and making sure everything follows the proper procedure. However, sometimes, a judge may make a mistake or commit misconduct, which would mean the accused would not get a fair trial if it continued. 

If the judge seriously missteps—such as by making inappropriate comments about the accused—this can be the basis for calling a mistrial. Another example of when a judge’s actions may be grounds for a mistrial is if they follow the incorrect procedure. For example, they might unjustifiably allow the case to proceed without a complaining witness. 

How Does a Mistrial Happen?

A mistrial happens when someone—such as the judge or one of the attorneys—makes an error that invalidates the trial. The mistake should be something so serious that it undermines the purpose of the trial, which is to administer justice. In other words, someone can call a mistrial if the outcome of the trial might be because of the mistake rather than the actual merits of the case. 

The judge can call a mistrial on their own even if one of the attorneys has not requested it. Another way a mistrial is called is if one of the lawyers asks the judge to declare one. Someone can call a mistrial anytime before the jury returns a verdict about the case. 

What Are the Consequences of a Mistrial?

When there is a mistrial, the case is essentially on pause until a new trial occurs. Since the prosecution is bringing the charges, it’s primarily up to them to decide how to proceed. For example, they might drop the charges completely because they realize they don’t have a solid case against the accused. Or they might decide to go forward with a new trial at a later date. 

Does a Mistrial Always Result in a Criminal Case’s Dismissal?

A mistrial may or may not result in the prosecution dropping the charges against the accused. If the prosecution doubts its ability to meet the high burden of proof, it may decide to dismiss the charges. Another possibility is for the prosecution to continue bringing the charges against the accused; however, they may modify how they present information to the jury, for example. 

In terms of case dismissals, it’s worth noting that the judge can dismiss the case in a couple of different ways. The judge can dismiss the case “nolle prosequi,” which means the prosecution has decided not to bring the charges against the accused. If the case is dismissed nolo contendere, it means the accused agreed not to fight against the charges being brought against them. If the judge does dismiss the case, the language they use to express this indicates what can happen next.

Mistrials vs Hung Juries: Is There a Difference?

A mistrial is a broad term used to describe a situation where the trial is called off because of a mistake. In contrast, a hung jury is where not all 12 jurors were able to reach the same conclusion about the case. 


A mistrial occurs when the judge calls off the current trial because of a significant error or misconduct that undermines the purpose of courtroom proceedings. In most situations, there are no specific grounds for a mistrial. In other words, the fact that the mistake swayed the proceedings unfairly is the reason for the mistrial—not because of a restrictive list. 

When a mistrial happens, the current trial is canceled, and the prosecution may decide to dismiss the charges or continue with a new trial later on. In most situations, someone can call a mistrial so long as the jury hasn’t made a final decision—e.g., issued a verdict—in the case. 

Hung Jury 

A hung jury is one possible reason someone can use to declare or request a mistrial. It refers to a situation where the jury is divided about whether the accused is guilty or not guilty. All 12 jurors need to agree on the outcome for the verdict to be valid. If this doesn’t happen, then it’s called a hung jury. 

Does Double Jeopardy Protect You if There’s a Mistrial?

Generally speaking, the Constitution of the United States of America protects people from going on trial—being put in jeopardy—for the same event on more than one occasion. For example, the prosecution can’t proceed with a trial on X offense once and then try to put the case on trial a second time based on the same conduct.  

In the context of double jeopardy and mistrials, the court has held that mistrials typically have no bearing on double jeopardy. Rather than being two separate and complete proceedings, the second trial is a continuation of the first one. Since the first trial was declared invalid and never completed—e.g., no guilty or not guilty verdict was entered—it doesn’t count. 

Martin & Reed, LLC: Colorado Criminal Defense Attorney Here To Fight for You

If you are facing serious charges and believe the judge or one of the attorneys did something they shouldn’t have, it may be time to reach out for legal help. The grounds for and what happens in a mistrial depend on each individual circumstances. Consulting with a lawyer gives you a chance to understand what went wrong and what your options are going forward. 

We respect your right to a fair trial and welcome the opportunity to work with you to develop a strong strategy to make sure you get one. The award-winning legal team at Martin & Reed, LLC, has earned a place on the National Association of Distinguished Counsel, a position reserved for the top 1% of law firms in the United States. Reach out to our compassionate advocates today by calling (970) 539-9377 to schedule an initial, no-obligation consultation to discuss your legal needs.