Massachusetts General Laws Part IV. Crimes, Punishments and Proceedings in Criminal Cases (Ch. 263-280) Ch. 268, § 33

Whoever falsely assumes or pretends to be a justice of the peace, notary public, sheriff, deputy sheriff, medical examiner, associate medical examiner, constable, police officer, probation officer, or examiner, investigator or other officer appointed by the registrar of motor vehicles, or inspector, investigator or examiner of the department of public utilities or the department of telecommunications and cable, or investigator or other officer of the alcoholic beverages control commission, or investigator or other official of the bureau of special investigations, or examiner, investigator or other officer of the department of revenue, and acts as such or requires a person to aid or assist him in a matter pertaining to the duty of such officer, shall be punished by a fine of not more than four hundred dollars or by imprisonment for not more than one year.