The tapes will be released on Wednesday afternoon by the town's law firm, Cohen & Wolf of Danbury.
There were seven 911 calls made to the local police department.
The longest call to Newtown police was from custodian Rick Thorne, who was on the phone with a dispatcher for more than 10 minutes. His call was cut off when Newtown police officers temporarily detained him.
There also were numerous 911 calls made to Troop L in Litchfield, which received the cellphone calls from, among others, a teacher who was shot in the foot and a parent locked in the room where Principal Dawn Hochsprung had been holding a meeting when the shooter(s) entered the school. Hochsprung and school psychologist Mary Scherlach ran out of the room and were the first two killed.
Those calls are the custody of the state police and are not among the ones that will be released by Newtown officials.