Two appellate court justices on Tuesday grilled both sides in a dispute over whether the police files from a 53-year-old unsolved murder can be released under the state’s open-records law.

Plaintiff John Q. Kelly is appealing Cook County Circuit Judge Anna Helen Demacopoulos’ December 2016 ruling that the village of Kenilworth is still conducting an “active and ongoing” investigation into the September 1966 murder of Valerie Percy, the daughter of a prominent businessman and future U.S. senator. She was 21 when she was found stabbed and beaten to death in the family home.

Tuesday’s oral arguments before the 1st District Appellate Court centered around Freedom of Information Act requests Kelly sent to Kenilworth, the Illinois State Police, the Cook County Medical Examiner’s Office and the Cook County State’s Attorney’s Office in 2016.

Those public entities rejected his FOIA requests, saying there was an active and ongoing investigation into Percy’s murder. FOIA allows public bodies to withhold records if they would interfere with a law enforcement investigation. Kelly filed suit in response.

Kelly, who grew up in Kenilworth, is now a New York-based attorney who has worked on several high-profile wrongful death cases, including the civil lawsuit filed by the estate of Kathleen Savio, who was murdered by her husband, former Bolingbrook police officer Drew Peterson.

Demacopoulos based her ruling, in part, on an affidavit from Kenilworth Police Chief David Miller that was filed under seal; she noted that the details of the affidavit have not been shared with anyone, including the other defendants.

The judge said Miller’s affidavit left “no doubt this is an active ongoing criminal investigation.”

Kelly’s attorney, Matthew V. Topic with Loevy & Loevy, argued before 1st District Appellate Justices Thomas E. Hoffman and Bertina E. Lampkin that he, as the plaintiff’s attorney, should have been allowed to examine Miller’s affidavit.

Justice Shelvin Louise Marie Hall, the third justice, was unable to attend the oral arguments. Hoffman said she will have access to the argument’s transcript.

Topic’s request for Miller’s affidavit was questioned by the justices.

“The court was reluctant to agree that I, as the attorney, should be able to see that affidavit,” Topic said in an interview following oral arguments.

Topic argued Demacopoulos should have done a private inspection of all the documents Kelly is requesting. The circuit judge only examined some recent documents, some of which were released. But Topic said some of the documents that weren’t examined and weren’t released are likely decades-old and pertain to dead ends in the investigation.

But 20,000 pages of documents are at issue in this case, and both Hoffman and Lampkin questioned the feasibility of a Cook County judge reviewing them all to determine where they’re exempted from release under FOIA.

Topic said he is open to Demacopoulos reviewing a “truly representative” sample of the documents they want released.

The justices signaled they were sympathetic to Topic’s argument that some of the documents should be released. They pressed Kenilworth’s attorney, Christopher J. Murdoch of Emry Murdoch LLC, on how they could justify a FOIA exemption for documents relating to people who are no longer suspects in Percy’s murder.

In response, Murdoch said it’s possible that old records that are seemingly useless could suddenly become important to the investigation. He didn’t give specifics, but Murdoch said that, had Kelly’s FOIA request been filed years earlier, the village might have released information “that is pertinent now.”

Hoffman went further, asking how could documents showing the layout of the Percy family house, where Valerie was found dead, could be shielded from disclosure. Murdoch argued that the public release of documents could harm the investigation because witnesses might come forward with new information because they had their “memories refreshed.”

During oral arguments, Topic said that letting Demacopoulos’ ruling stand could make it harder to obtain records from law enforcement agencies, saying it would “open the secrecy floodgates.”

Topic elaborated on his point in the interview: “Under the circuit court’s approach, the city [of Chicago] could have withheld the Laquan McDonald video for as long as the investigation was open.”

Topic was one of the attorneys who represented independent journalist Brandon Smith as he sued for the release of the dashcam video that depicted McDonald being shot 16 times by Chicago police officer Jason Van Dyke. Cook County Associate Judge Franklin U. Valderrama in November 2015 ruled that the Chicago Police Department cannot use the ongoing investigations of separate law enforcement agencies to justify its own exemption from complying with the FOIA request. Such an exemption only applies to items under its own internal investigation.

Cook County Assistant State’s Attorney Cristin K. Duffy and Assistant Attorney General Evan Siegel also spoke during oral arguments on behalf of the state’s attorney’s office and the Illinois State Police, respectively.

Kelly was also represented by Joshua Burday and Merrick J. Wayne of Loevy & Loevy.

It is not known when a ruling will be made on the request.

The case is John Q. Kelly v. Village of Kenilworth, et al., No. 1-17-0780.