By John Christoffersen

Associated Press

NEW HAVEN, Conn. — There is no doubt who is responsible for the Newtown school massacre. The shooter is dead and the prosecutor handling the case has said he does not expect any charges.

Yet authorities are continuing to keep search warrants and police records secret. Media outlets have pressed for the release of more records, which could shed light on a crime that has revived the national debate over gun control and could change the way guns are regulated.

Related feature Special Report: Newtown School Shooting In this special report, we bring news from the scene and offer expert perspective on the tragedy.

The massacre has led to proposals for universal background checks on gun buyers and bans on assault weapons and high-capacity ammunition magazines. It also prompted reviews of school security and mental health care and led to proposed legislation in Connecticut that would forbid arcades and other establishments from allowing children under 18 to play point-and-shoot video games.

The 20-year-old shooter, Adam Lanza, killed his mother at their home before killing 20 first-graders and six educators at Sandy Hook Elementary School on Dec. 14. He killed himself as police arrived.

Prosecutor Stephen Sedensky III successfully argued in December to keep search warrant affidavits and applications related to Lanza's house and the car he drove to the school sealed for 90 days, saying disclosure would jeopardize an ongoing investigation. He said at the time no arrests were anticipated but had not been ruled out.

News media advocates say the records should be unsealed, arguing the public has a right to see such records, which include what was found in the house and car. They say records may be sealed only when an investigation would be hurt by disclosure.

"There seems to be absolutely no reason that they would need to. It's not going to jeopardize the case in any way," said Linda Petersen, chairwoman of the Freedom of Information Committee of the Society of Professional Journalists.

William Fish, an attorney who has represented the news media in high-profile cases that were sealed in Connecticut, also said the sealing does not appear justified since no prosecution is likely. He conceded, however, that "it's not a surprise to me that a court has in fact sealed the records just because it's so horrible."

Newtown police denied requests by The Associated Press for 911 calls and any police reports involving Lanza or his family. State police also declined to release records, citing the pending investigation.

In an editorial last week, The Hartford Courant said such records should be released sooner, not later, since they might answer the public's questions about the murders and could guide legislators making policy decisions in reaction to the crime.

Richard Hanley, graduate journalism director at Quinnipiac University, said he understood the 90-day sealing while the investigation unfolded but said there should be no extension of that sealing.

"This was a case that had a profound impact on people beyond the immediate area and it will have a profound impact on public policy," Hanley said Monday. "It's imperative that the authorities release the full investigative records, the 911 calls and other documents relative to this slaughter, because the overriding interest is the public's right to know."

Sedensky, the prosecutor, noted that authorities have disclosed details about the weapons used in the shooting: a Bushmaster semi-automatic rifle was used to kill the children and educators and a handgun to kill himself. He said he advised Newtown officials not to disclose the 911 calls.

Danbury Superior Court Judge John F. Blawie on Dec. 27 granted the 90-day seal on search warrant affidavits and applications after concluding that the state's "interest in continuing nondisclosure substantially outweighs any right to public disclosure at this time."

Sedensky said he has not decided yet whether to seek an extension of the sealing. A police report on the probe may not be ready until the summer, he said.

In denying a request by the AP for police reports and 911 calls, the Newtown Police Department said releasing the documents was prohibited by state law "as information to be used in a prospective law enforcement action." AP's request sought all police calls for service to the Lanza house and to Sandy Hook Elementary School, 911 calls and any police reports involving Lanza and his family.

Police Chief Michael Kehoe has said there were only two calls to the Lanza house several years before the shooting. One was in 2006 in which Lanza's mother Nancy reported someone rang the doorbell and ran off and the other was to report a larceny in 2003 that turned out to be in another jurisdiction, Kehoe said.

Copyright 2013 Associated Press