Mass. Gen. Laws ch. 21A § 10C
The director, deputy directors of enforcement, chiefs of enforcement and all deputy chiefs of enforcement, law enforcement coordinators, and the wardens, as defined in section 1 of chapter 131, and all environmental police officers and deputy environmental police officers shall have and exercise throughout the commonwealth, subject to such rules and regulations as the director, with the approval of the secretary, may from time to time adopt, all the authority of police officers and constables, except the service of civil process. Such rules and regulations shall be filed with the state secretary in accordance with section 37 of chapter 30. The director may authorize in writing any such deputy directors of enforcement, chiefs of enforcement, deputy chiefs of enforcement, and any environmental police officer to have in their possession and carry a firearm, revolver, club, billy, handcuffs, twisters, or any other weapon or article required in the performance of official duty.
Mass. Gen. Laws ch. 21A, § 10C