In a decision Wednesday, the commission -- which administers and enforces the state's freedom of information law -- recommended Newtown police release the Sand Hook tapes, CNN reported.
The commission found 911 tapes are not covered by a new state law, passed in response to the shooting in Newtown, that exempts photographs of victims' bodies and some other material from disclosure.
A report by a lawyer for the commission in August found police in Newtown should not have followed a request by the state attorney general to keep the tapes secret. The report said police did not begin looking for the tapes until May, months after the Associated Press wire service first requested them in December.
Adam Lanza, a former Sandy Hook student, killed his mother in December 2012 and then drove to the school, where he gunned down 20 students and six staff members. He killed himself as police closed in.
The tapes are not likely to become public soon, CNN said. Local officials can appeal the commission's recommendation.
Stephen Sedensky III, the state's attorney in Danbury, has said releasing the tapes could subject witnesses to intimidation or harassment.