The 2014 deaths of Cooper University Health System's CEO John P. Sheridan and his wife, Joyce, may have come at the hands of a killer, but New Jersey and Somerset County officials will not say whether a new criminal investigation will be launched.

On Friday, the New Jersey Attorney General's Office announced, with little comment beyond a news release, that the state medical examiner had changed John Sheridan's manner of death from suicide to undetermined.

The ruling by the medical examiner also raises serious questions about the credibility of conclusions in 2015 that John Sheridan went on a violent rampage, fatally stabbing his wife and setting fire to their bedroom. The couple's four sons disputed those findings. Last year, they sued to have their father's death certificate changed, which led to Friday's announcement.

The state did not indicate whether a criminal investigation into the couple's deaths would be reopened, referring questions to the Somerset County Prosecutor's Office, which had no comment.

Five independent experts interviewed by the Inquirer on Friday believe the criminal investigation should be reopened.

"They ought to go back to the crime scene and take a different view of what might have occurred," said private attorney Edwin Stier, a former state and federal prosecutor who once served as chief for the criminal division of the New Jersey Attorney General's Office.

"I'm not suggesting it's going to be easy. But easy or not, it has to be done, and we've got to find the best resources to do it," said Stier. "Clearly the investigation was grossly mishandled the first time around."

Stier said if the Sheridans were both murdered, there is someone, or more than one person, who poses a serious threat to the public given the "horrific" circumstances of the couple's deaths.

A new probe should not rely on the initial investigative files, and should not rule out the possibility there is still evidence in the couple's now vacant Montgomery Township house, Stier said.

Former New Jersey Attorney General John Farmer said it seems unlikely investigators can solve the case based solely on the forensic evidence.

"There's not a lot of additional investigation you can do except wait for a break to happen," said Farmer, who now teaches at Rutgers School of Law-Newark.

He said nearly half of all homicides remain unsolved and with the passage of time, the Sheridan deaths now fall into the "cold case" category.

Still, he said, "I think it's an admirable step that (the medical examiner) took. It represents an honest effort on their part to get to the bottom of what happened."

Both Farmer and Stier were among nearly 200 people who last year signed an open letter asking that the Sheridan case be reopened.

The Sheridans' sons - Mark, Matt, Tim, and Dan - have said from the start that their parents had a loving marriage of 47 years and that their father did not murder their mother, a retired schoolteacher.

The report released Friday by New Jersey Medical Examiner Andrew Falzon indicates the manner of death could be further amended if new information is found.

Falzon's report did not speculate whether John Sheridan was murdered. Falzon did, however, note the weapon that caused Sheridan's five stab wounds has not been recovered, an issue the outside experts interviewed by the Inquirer said more likely points to murder.

Peter Aseltine, a spokesman for the Attorney General's Office, said Falzon's report "speaks for itself," and questions about the investigation should be sent to the Somerset County Prosecutor's Office.

Last year, Prosecutor Michael Robertson said he would not decide whether the criminal case should be reopened until the medical examiner made a decision.

"At this time we have no comment," Robertson said Friday. "However, I want to assure the public and the residents of Somerset County that we have no reason to believe that they should be fearful of their safety."

Renowned forensic pathologist Cyril Wecht said the statement by Robertson is meant more to "comfort" the public, and called it "meaningless."

"How can he make such a statement? There is no basis for it," said Wecht, with 50 years experience as a pathologist. "What he's really saying is he doesn't believe this is murder."

The Sheridans were found dead on Sept, 28, 2014, in the master bedroom of their home. Both had been stabbed repeatedly, and suffered severe burns from a fire intentionally set in the bedroom. John Sheridan also had five broken ribs, and a chipped front tooth.

The deaths shocked New Jersey's political and social elite who knew the Sheridans for their devotion to public service, especially John Sheridan who had served as transportation commissioner for Gov. Tom Kean, and was on Gov. Christie's transition team.

The couple's sons believe investigators assumed the deaths were a murder-suicide, overlooked evidence indicative of a double murder, and manipulated the facts to fit their theory.

The family hired its own forensic pathologist, Michael Baden, who performed a second autopsy on John Sheridan and determined the two large kitchen knives found in the bedroom could not have caused John Sheridan's narrow wounds. He also concluded the broken ribs and chipped tooth were indicative of an attack.

Despite that, in the spring of 2015, then Somerset County Prosecutor Geoffrey Soriano concluded that Sheridan was responsible for the crimes.

The Sheridan sons in late 2015 petitioned the state medical examiner's office to change the manner of death, and later sued to force state officials make a decision after their petition sat idle for months.

According to Falzon's report, his review included a new look at the previous autopsy conclusions, Baden's report, autopsy and crime scene photographs, expert reports including DNA analysis, Sheridan's medical records, and a report issued by Soriano.

Falzon concluded that Sheridan's cause of death was the result of "sharp force injuries and smoke inhalation." This was the same conclusion reached in 2015, by the regional pathologist, Eddy Lilavois.

In changing the manner of death to undetermined, Falzon wrote, "All this is unfortunately compounded by the extensive destruction of the scene by the fire."

"Should additional information regarding the case become available in the future, the case will be re-evaluated and amended if necessary," Falzon concluded.

The family is hoping for a new criminal investigation.

"It's been a long two-plus years to get to this point. We feel a huge wrong has been made right, at least in part," Mark Sheridan said Friday.

"Unfortunately, we still don't know who killed our parents and so while we accept today's decision as a vindication of what we've said all along, we have a long way yet to go.

"On behalf of the Sheridan family, I want to thank the State Medical Examiner for doing the right thing and exercising the courage to admit that a mistake was made."

Two prominent South Jersey defense attorneys said they also believe the case should be reopened, but even if a suspect is found, a prosecution would not come easily.

Somerdale attorney Gil Scutti, a former Philadelphia prosecutor, said the two different rulings on manner of death present problems going forward.

"As a former prosecutor, I agree that they have an obligation to reopen the investigation," Scutti said. "As a current defense attorney, I question how they can prove a homicide beyond a reasonable doubt."

Haddonfield attorney Glenn Zeitz said the change to the death certificate is significant.

"I think it is meaningful to the family because it removes a cloud that has been hanging over their family and the legacy of their father," Zeitz said. "But it doesn't solve the case of who done it, which I am sure to them is as equally as important."

Zeitz questioned why Falzon did not issue a more detailed report of his findings. "Where's the beef? And why did it take this long? He could have said this months ago."

bboyer@phillynews.com

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