Mass. Gen. Laws ch. 41 § 99G
The regional police district commission shall annually determine the amounts necessary to be raised to maintain and operate the district police during the ensuing calendar year, and the amounts required for payment of debt and interest incurred by the district which will be due in said year, and shall apportion the amount so determined among the member towns in accordance with the provisions of section ninety-nine I. The amounts so apportioned for each town shall, prior to December thirty-first in each year, be certified by the regional police district treasurer to the treasurers of the member towns. Each town shall, at the next annual town meeting, appropriate the amounts so certified and the town treasurer shall pay the amount so appropriated to said district forthwith.
The treasurer of any member town of a regional police district with the approval of the board of selectmen may, during the interval between January first and the date when such town makes the annual appropriation of the amount apportioned to it as provided in the first paragraph, make payments to the regional police district from the treasury of such town from any funds available therein. Such payments shall not exceed in the aggregate one third of the amount so apportioned and shall be charged against such appropriation.
For the purpose of organizing a department as provided in section ninety-nine J, the treasurer of any member town of a regional police district with the approval of the board of selectmen may, during the interval between the establishment of the commission as provided in section ninety-nine F and the following December thirty-first, make payments to the regional police district from the treasury of such town from any funds available therein. Such payments shall not exceed three thousand dollars per member town and shall be charged against the first annual appropriation.
Mass. Gen. Laws ch. 41, § 99G