Mass. Gen. Laws ch. 22C, § 22

Except as otherwise provided by a collective bargaining agreement in accordance with the provisions of chapter one hundred and fifty E, evaluation reports of the performance of each member of the state police shall be submitted annually to the colonel by the supervisor to whom such member has directly reported for said annum; provided, however, that whenever possible, if the supervisor of such member shall be changed by transfer of said supervisor or by transfer of such member, such evaluation report be completed prior to such change in supervision. Such evaluation reports shall be filed annually.