In a Massachusetts Criminal Trial, of any type, whether murder or an OUI, the verdict must be unanimous, meaning that all six jurors have to agree whether the verdict is guilty or not guilty. If jurors cannot reach a unanimous verdict, it is called a hung jury and the Commonwealth is permitted to retry the case. The first Bill Cosby trial ended in a hung jury. In every criminal trial, a jury should be instructed on this principal of law. The jury misunderstood this; possibly the instruction should be simplified telling the jury directly that a conviction cannot rest on a vote of five to one or four to two.
In Commonwealth v. Dibenedetto, a trial from the Worcester District Court the jury was under the mistaken belief that only a majority was required to return a verdict. When the judge learned of this after thanking the jurors following the verdict, he instructed them that the verdict must be unanimous. After his reinstruction following the first verdict, the jury then again returned a guilty verdict.
The Appeals Court held that after the verdict is recorded the verdict is final. After the verdict is rendered, the judge is precluded from inquiring into the propriety of the jurors deliberation or decision making. The Appeals Court stated that the prohibition against impeachment of a verdict is not absolute. Juror testimony, the Court stated, can be used to show the following: unauthorized site visits, improper communication between parties, or consideration of facts not in evidence, as well as racial bias.