There are two types of trials in Massachusetts. All defendants are entitled to a jury trial, however they can waive a jury and have a bench trial.
BENCH TRIAL IN MASSACHUSETTS
A bench trial is a trial without a jury. It is conducted by a Judge. The judge rules on issues of law and fact. The judge decides all of the issues in the case as well as imposes a sentence if the judge finds the defendant guilty of the crime. A bench trial does not have to be selected until the day of trial. Typically someone select a bench trial because they have a clear issue and feel confident of ruling by the judge. Judges have track records and are easier to predict what they will do rather than a jury.
JURY TRIAL IN MASSACHUSETTS
A jury in District Court in Massachusetts consists of six people randomly selected from community. In Superior Court there are 12 jury members. In selecting a Massachusetts district court criminal jury both sides, the prosecutor and the defense attorney are allowed to strike as many members for cause as well as two preemptory challenges. A challenge for cause must be approved by a judge and be for a specific reason like the person is unable to be fair. A preemptory challenge in Massachusetts can be used for any reason. It is the jury's decision to decide if the person is guilty or not guilty. The judge decides issues of law and the jury decides issues of fact. A jury trial is normally longer and more formal than a bench trial.