Massachusetts Criminal Procedure Rule 18: Presence of Defendant
(Applicable to District Court and Superior Court)
(a) Presence of Defendant. In any prosecution for crime the defendant shall be entitled to be present at all critical stages of the proceedings.
(1) Defendant absenting himself. If a defendant is present at the beginning of a trial and thereafter absents himself without cause or without leave of court, the trial may proceed to a conclusion in all respects except the imposition of sentence as though the defendant were still present.
(2) Waiver of Presence in Misdemeanor Cases. A person prosecuted for a misdemeanor may at his own request, with leave of court, be excused from attendance if represented by counsel or an agent authorized by law and may be excused from attendance without leave of court if so authorized by the General Laws.
(3) Presence Not Required. A defendant need not be present at a revision or revocation of sentence pursuant to rule 29 or at any proceeding where evidence is not to be taken.
(b) Presence of Corporation. A corporation may appear by a duly authorized agent for the purposes of this rule.