Mass. Gen. Laws ch. 66 § 17
Except as otherwise provided by law, all public records shall be kept in the custody of the person having the custody of similar records in the county or municipality to which the records originally belonged; provided, however, that the custodian of public records may enter into a contract for the storage of records containing public record information, but no contract for the storage of public records shall be entered into if the contract prevents or unduly restricts a records access officer or custodian of records from providing or storing the records in accordance with this chapter. Records not directly in the custodian's possession shall be considered in the custody of the custodian if subject to a contract for the storage of public records that is permitted by this section. If the custodian does not have custody of public records, the custodian shall demand delivery from any person unlawfully having possession of the records, and the records shall immediately be delivered by such person to the custodian. A person who refuses or neglects to perform any duty required by this section shall be punished by fine of not more than $20.
Mass. Gen. Laws ch. 66, § 17