Massachusetts General Laws Part IV. Crimes, Punishments and Proceedings in Criminal Cases (Ch. 263-280) Ch. 279, § 34

When a convict is sentenced to pay a fine or to be imprisoned, the clerk of the court shall forthwith make out and deliver to the sheriff or to some officer in court a duly certified transcript from the minutes of the court of the conviction and sentence, which shall authorize the officer to execute such sentence, and he shall execute it accordingly. When such convict is sentenced to be imprisoned in a correctional institution of the commonwealth, except the Massachusetts Correctional Institution, Bridgewater and the Massachusetts Correctional Institution, Framingham, the officer authorized to execute such sentence shall deliver him to the reception center established in accordance with the provisions of section twenty of chapter one hundred and twenty-seven for examination and classification.