MADISON, Conn. (AP) — Police in a wealthy Connecticut town where the 2010 killing of Barbara Hamburg remains unsolved are fighting a judge’s order to turn over investigative files to two documentary filmmakers, including Hamburg’s son.

Madison police earlier this month appealed the order to the state Appellate Court, in a case that could have wide implications for access to police cold case files in the state, the Hartford Courant reported Saturday.

Barbara Hamburg was found slain outside her home on March 3, 2010, when Madison Hamburg was a teenager. The documentary looked at suspicions his family and police had about his father, Jeffrey Hamburg, who has denied involvement.

Hamburg’s son, Madison Hamburg, and producer Anike Niemeyer requested the files while filming the “Murder on Middle Beach” documentary series on Barbara Hamburg’s killing that ran on HBO last year. The police department rejected the request.

They appealed to the state Freedom of Information Commission, which ruled last year that police must release the files. Police initially turned over two boxes of materials to Madison Hamburg and Niemeyer, but later reversed course and appealed that ruling to Superior Court.

Judge Daniel Klau upheld the commission’s ruling last month, but police appealed that decision to the state Appellate Court last week. The judge said the case raises questions about when to publicly release investigative files on a cold case.

Madison police did not return messages from the Courant seeking comment. Police have argued they do not have to release the documents because the investigation remains open.