Mass. Gen. Laws ch. 12 § 10
He shall take cognizance of all violations of law or of orders of courts, tribunals or commissions affecting the general welfare of the people, including combinations, agreements and unlawful practices in restraint of trade or for the suppression of competition, or for the undue enhancement of the price of articles or commodities in common use, and shall institute or cause to be instituted such criminal or civil proceedings before the appropriate state and federal courts, tribunals and commissions as he may deem to be for the public interest, and shall investigate all matters in which he has reason to believe that there have been such violations. Whenever it appears to the attorney general that the commonwealth or any city, town, or other governmental agency, body or authority established under the laws of the commonwealth has been so injured or damaged by any conspiracy, combination or agreement in restraint of trade or commerce or similar unlawful action, as to entitle the commonwealth, a city, town, or other such governmental agency, body or authority to a right to bring any action or proceeding for the recovery of damages under the provisions of any federal anti-trust or other similar law, the attorney general shall have authority to institute and prosecute any such actions or proceedings on behalf of the commonwealth or of any city, town, or other governmental agency, body or authority established under the laws of the commonwealth, and shall have authority to intervene on behalf of the commonwealth or of any city, town or other governmental agency, body or authority in such actions or proceedings. For the purposes of this section, he may appoint necessary assistants, with such compensation as, with the approval of the governor and council, he may fix, and may expend such sums as may be approved by the governor and council. In criminal proceedings hereunder he may require district attorneys to assist him and under his direction to act for him in their respective districts.
Mass. Gen. Laws ch. 12, § 10