Mass. Gen. Laws ch. 40 § 36B
Each cell utilized for the detention of persons within a city, town, or state lockup facility which is under the jurisdiction of a local police department or the state police shall have a protective covering of high-impact, transparent wall facing. Such protective covering shall cover all bar structures accessible to such detained persons. Adequate ventilation shall be provided to persons detained in the cell.
At least one such cell within such lockup facility shall have installed within it, but beyond the access of any person detained within such cell, an electronic audio system whereby a police officer or other lockup personnel at the duty desk within such lockup facility is brought within audible range of such cell; provided, however, that no such electronic audio system is required to be installed if at least one such cell within such lockup facility is within audible range of the duty desk without electronic assistance.
Each occupied cell within such a lockup facility should be physically or visibly checked by a law enforcement officer or other lockup personnel as often as is required by a reasonable standard of care of detainees.
Every lockup facility shall have installed within the cell area an electronic security device which will record the date and time of day of each cell check made by a law enforcement officer or other lockup personnel. All checks made shall be recorded on such electronic security device.
Mass. Gen. Laws ch. 40, § 36B