Mass. Gen. Laws ch. 12, § 5N
(1) Notwithstanding any general or special law, procedural rule or regulation to the contrary, whenever the attorney general or a designee has reason to believe that a person may be in possession, custody or control of documentary material or information relevant to a false claims law investigation, the attorney general or a designee may, before commencing a civil action under paragraph (1) of section 5C or other false claims law, or making an election to intervene under paragraph (3) of said section 5C, issue in writing and cause to be served upon such person, a civil investigative demand requiring such person to:
(2) Service of a demand pursuant to paragraph (1) may be made by: