Mass. Gen. Laws ch. 277B, § 3: Nature and scope of investigation

Section 3. The superior court justice appointed to preside over the grand jury shall consult with the attorney general and district attorney for the relevant district about the nature and scope of the investigation and shall thereafter designate and authorize an existing county grand jury to serve as a statewide grand jury for the purposes of the investigation specified in the written application or, alternatively, the superior court justice may convene and preside over a specially-empaneled statewide grand jury.