Mass. Gen. Laws ch. 212, § 21: Special jury sittings for criminal business

Section 21. The chief justice may, by written order to the sheriff, order a special jury for a sitting for criminal business to be held in any county at such time and place as may be appointed in such order. The sheriff shall give notice thereof as directed in the order therefor; but no person under recognizance to answer to an indictment or to a criminal complaint shall be held to appear at such special sitting or at any time and place other than the regular sittings of the court, unless duly notified by written summons from the clerk.