Mass. Gen. Laws ch. 60 § 97
If a collector ceases to hold the office of collector for any reason, all his accounts, records and papers, including his warrant, which relate to the assessment and collection of taxes in his town shall, forthwith after an audit thereof has been made by a competent accountant, be deposited by him, or his executor or administrator, or any other person into whose possession they may come, with the assessors of such town, who thereupon shall turn over his uncollected tax lists to his successor, together with their warrant, which shall cover the uncollected accounts of the original commitment as shown on said lists and shall also turn over all his accounts, records and papers, including his warrant, so deposited with them, except said lists, to the clerk of said town. If the collector is his own successor, he shall complete the collection of the taxes as a part of the duties of his new term of office and not as a part of the duties of his former term of office.
Mass. Gen. Laws ch. 60, § 97