Mass. Gen. Laws ch. 93H § 4
Notwithstanding section 3, notice may be delayed if a law enforcement agency determines that provision of such notice may impede a criminal investigation and has notified the attorney general, in writing, thereof and informs the person or agency of such determination. If notice is delayed due to such determination and as soon as the law enforcement agency determines and informs the person or agency that notification no longer poses a risk of impeding an investigation, notice shall be provided, as soon as practicable and without unreasonable delay. The person or agency shall cooperate with law enforcement in its investigation of any breach of security or unauthorized acquisition or use, which shall include the sharing of information relevant to the incident; provided however, that such disclosure shall not require the disclosure of confidential business information or trade secrets.
Mass. Gen. Laws ch. 93H, § 4