Mass. Const. pt. II, ch. I, § II, art. VIII
The senate shall be a court with full authority to hear and determine all impeachments made by the house of representatives, against any officer or officers of the commonwealth, for misconduct and mal-administration in their offices. But previous to the trial of every impeachment the members of the senate shall respectively be sworn, truly and impartially to try and determine the charge in question, according to evidence. Their judgment, however shall not extend further than to removal from office and disqualification to hold or enjoy any place of honor, trust, or profit, under this commonwealth: but the party so convicted, shall be, nevertheless, liable to indictment, trial, judgment, and punishment, according to the laws of the land.