Mass. Gen. Laws ch. 159C, § 10: Time limitations for actions or proceedings

Section 10. No action or proceeding shall be brought pursuant to this chapter: (i) more than 3 years after the person bringing the action knew or should have known of the occurrence of the alleged violation; or (ii) more than 3 years after the termination of a proceeding or action arising out of the same violation by the commonwealth, whichever is later.