Mass. Gen. Laws ch. 140, § 201

A sheriff, marshal or their deputies, a constable or police officer may at any time enter a billiard, pool or sippio room, bowling alley, skating rink, the licensed premises of a common victualler or room connected therewith, or a grove required to be licensed under section one hundred and eighty-eight, or any building therein, for the purpose of enforcing any law; and whoever obstructs or hinders the entrance of such officer shall be punished by a fine of not less than five nor more than twenty dollars.