Mass. R. Evid. 515
Unless otherwise required by law, information given to governmental authorities in order to secure the enforcement of law is subject to disclosure only within the discretion of the governmental authority.
Mass. Guid. Evid. 515
This section is derived from Worthington v. Scribner, 109 Mass. 487, 488-489 (1872), and Attorney Gen. v. Tufts, 239 Mass. 458, 490-491 (1921). See also District Attorney for the Norfolk Dist. v. Flatley, 419 Mass. 507, 510-511 (1995).
Although this privilege is described as "absolute," it is qualified by the duty of the prosecutor to provide discovery to a person charged with a crime. See Mass. R. Crim. P. 14. Moreover, as to certain kinds of information, the privilege is also qualified by the Massachusetts public records law. See G. L. c. 66, § 10. General Laws c. 4, § 7, Twenty-sixth (f), provides that investigatory materials, including information covered by this privilege, are regarded as a public record and thus subject to disclosure even though the material is compiled out of the public view by law enforcement or other investigatory officials, provided that the disclosure of the investigatory materials would not "so prejudice the possibility of effective law enforcement that such disclosure would not be in the public interest." Rafuse v. Stryker, 61 Mass. App. Ct. 595, 597 (2004), quoting Bougas v. Chief of Police of Lexington, 371 Mass. 59, 62 (1976). See Worcester Telegram & Gazette Corp. v. Chief of Police of Worcester, 436 Mass. 378, 383 (2002) (describing the process for determining whether material is exempt from disclosure as a public record).
Section 509, Identity of Informer, Surveillance Location, and Protected Witness Privileges.