Mass. Gen. Laws ch. 263A § 3
In any criminal investigation or proceeding, the prosecuting officer with jurisdiction over the investigation or proceeding may file a petition with the board requesting witness protection services for a critical witness if the prosecuting officer certifies that such witness's participation in the investigation or proceeding places the witness at risk of harm including, but not limited to, intimidation or retaliatory violence. The petition shall include a proposed plan for protective services which shall include, but not be limited to, projected costs, method of protection and likely duration of services. The board shall review the petition as soon as possible and if, by a vote of 3 or more board members, finds that the petition and plan comply with the rules and regulations established by the board, the board shall assist the prosecuting officer to coordinate the efforts of state, county and local agencies to secure witness protection services. The board shall, subject to appropriation, reimburse the prosecuting officer for any witness protection related costs that comply with the regulations and guidelines established by the board.
Mass. Gen. Laws ch. 263A, § 3