Mass. Gen. Laws ch. 268, § 24: Neglect or refusal to assist officer or watchman

Section 24. Whoever, being required in the name of the commonwealth by a sheriff, deputy sheriff, constable, police officer or watchman, neglects or refuses to assist him in the execution of his office in a criminal case, in the preservation of the peace or in the apprehension or securing of a person for a breach of the peace, or in a case of escape or rescue of persons arrested upon civil process, shall be punished by a fine of not more than fifty dollars or by imprisonment for not more than one month.