Mass. Gen. Laws ch. 22C § 19
The colonel shall promulgate rules and regulations to provide a standard form or forms of uniform to be worn by members of the state police and to authorize such members to carry badges, revolvers, clubs, handcuffs, twisters or such other articles as may be required in the performance of their duties. The secretary of public safety and security may adopt regulations relative to the form, content and issuance of identification cards and to the carrying thereof by state police officers.
A uniform or any distinctive part thereof so prescribed shall be worn only by members of said department entitled thereto under said rules and regulations. Violations of this paragraph shall be punishable by a fine of not less than five hundred nor more than one thousand dollars.
Mass. Gen. Laws ch. 22C, § 19