After a verdict is reached in a civil case like a personal injury case, either the plaintiff or the defendant may move for a new trial. One reason the parties in a case may ask for a new trial is juror misconduct.
Juror misconduct can occur in many different ways. For instance, a juror who deliberately lied in response to a question during voir dire may be accused of juror misconduct. Also, jurors that disobey jury instructions may have committed juror misconduct. For instance, during jury instructions, juries are typically instructed to consider only the evidence they have heard in the courtroom when making their decision. Therefore, jury members who visit an accident scene or who talk about a case with their spouses or best friends (who are not on the jury) before reaching a verdict may commit juror misconduct because they have violated the rules given to them in their instructions. In many high-profile cases, juries are sequestered in order to prevent precisely this kind of intentional or accidental juror misconduct.
Juror misconduct is not always obvious. In a few cases, some kind of juror misconduct is obvious based on the verdict, especially if jurors have used verdict forms to walk them through their reasoning. If the jury has made an obvious mistake on the verdict forms or has asserted that two incompatible facts are both true, it is often reasonable for the parties or the court to suspect either intentional or accidental juror misconduct. For instance, suppose that on a verdict form in a car accident case, the jury writes that it believes the defendant is 100 percent liable for the accident and the injured plaintiff is 0 percent liable. However, the jury also writes that the defendant and the plaintiff should split the damages fifty-fifty, even though it decided the plaintiff was not at all responsible. Under the rules of comparative negligence, this result is inconsistent, and juror misconduct may become an issue.
In cases where the jury got something wrong on the verdict itself, the judge may try to find a way to fix the mistake rather than ordering a new trial. For instance, in the example above, the judge may send the jury back to the jury room for further deliberations, so the jury can decide whether it meant the plaintiff was 0 percent or 50 percent liable and adjust the damages amount accordingly. However, if the mistake is the result of a fundamental misunderstanding of the case by the jury, a new trial may be necessary.
More often, however, juror misconduct is not obvious from the verdict. If a party suspects juror misconduct, it must find other evidence to support its suspicions. At one time, most U.S. jurisdictions followed the “Mansfield Rule,” which prohibited parties who suspected jury misconduct from using juror testimony about what happened during the deliberations. Today, that rule has been softened to allow some kinds of juror testimony, but only on certain topics or in certain situations.
In order to win a motion for a new trial based on juror misconduct, a party must show not only that misconduct occurred, but that it was prejudicial to that party’s case – in other words, the misconduct had to disadvantage the moving party in a way that would not have happened without the misconduct. This requirement can be a high bar to meet. For instance, suppose that a plaintiff in a car accident case believes that the jury’s decision not to award her damages was based on misconduct. In order to get a new trial, the plaintiff has to show that, if the jury had acted properly, she would have won her case. If she would have lost anyway, she cannot win a new trial based on the juror misconduct.