During the 1976 Christmas season many Massachusetts retailers openly defied the Sunday Closing Laws (Blue Laws) by opening their stores. They did so because they believed themselves to be at a significant disadvantage compared with retailers just across the Massachusetts borders in adjacent States, who could legally open on Sundays. They sensed that public opinion was behind them, They also knew that a justice of the Supreme Judicial Court, while refusing to enjoin the laws' enforcement, had indicated his belief that the law was unconsititutional. The Governor and attorney general openly disagreed over whether the police should enforce the law. In the midst of this turmoil were the State's police chiefs who had to formulate local enforcement policy. A questionnaire was mailed to each of the 310 police chiefs to determine what policy they had taken towards enforcement, the reason for the police response, and who had communicated with the chief in the decisionmaking process; 44 percent of the questionnaires were returned. The results showed that chiefs experiencing violations reported exercising broad discretion and did not uniformly comply with the statutory enforcement mandate. The chiefs who prosecuted violators also reported that they became involved because of their own initiatives and not because of citizen requests for enforcement. The results further indicated that chiefs made few communications with nonpolice persons prior to making their policy decision. These results suggest that wider input should be made into the process by which chiefs decide enforcement policy. Legislatures could facilitate the development of control on police discretion by restructuring the statutory framework so as to provide for legitimized police discretion or by considering alternative methods for implementing administrative rulemaking in police departments. Tables, 29 references, and 9 notes are provided. (Author abstract modified)