Massachusetts General Laws Part III. Courts, Judicial Officers and Proceedings in Civil Cases (Ch. 211-262) Ch. 215, § 38

Oaths required in proceedings in the probate courts may be administered by the judge, register, first assistant register, assistant register, judicial case manager, assistant judicial case manager or session clerk in or out of court or by a justice of the peace or notary public and, when administered out of court, a certificate thereof shall be returned and filed or recorded with the proceedings, but the judge may require any such oath to be taken before him in open court.