Mass. Gen. Laws ch. 217 § 30
The judges of probate for the counties of Suffolk, Middlesex, Plymouth and Norfolk may appoint three officers, and the judges of probate for the counties of Essex and Worcester may appoint two officers to attend the sessions of the court for their respective counties. Such officers may be removed at the pleasure of the judge or judges of probate of their respective counties, and said judge or judges may fill any vacancy caused by removal or otherwise. Each court officer appointed hereunder for Suffolk, Middlesex, Worcester, Essex, Norfolk or Plymouth county shall give bond with sufficient sureties approved by a judge of his court for the faithful performance of his duties, in the sum of one thousand dollars, payable to the state treasurer. Each officer appointed hereunder shall serve the orders, precepts and processes issued by the probate court for which he is appointed or by a judge thereof; and shall at the expense of the commonwealth be furnished with a uniform such as the court shall order, which he shall wear while in attendance on said court.
Mass. Gen. Laws ch. 217, § 30