The death of the wife of Cooper Health System CEO John P. Sheridan Jr. has been ruled a homicide, while investigators have not determined how her husband died, records show.

A copy of the death certificate for Joyce Sheridan, obtained by The Inquirer on Tuesday, lists the manner of death as "homicide." Her husband's death certificate says "pending investigation."

The Sheridans both had multiple stab wounds when their bodies were pulled from a Sept. 28 fire in their home in the Skillman section of Montgomery Township, Somerset County, sources said last week.

Joyce Sheridan, 69, a retired teacher, was repeatedly stabbed in the upper body and chest, according to one of the sources, who like all the others spoke on the condition of anonymity because of the ongoing investigation.

The death certificate revealed that Joyce Sheridan was slain. There was no information on the cause of death. She was in cardiac arrest at the scene, according to a computer-aided dispatch report, and was pronounced dead at Princeton Medical Center, authorities said.

John Sheridan, 72, was stabbed in the neck and his jugular may have been slashed, according to the source. He was also stabbed on one side, the source said.

"What they're saying is that her wounds were delivered at the hands of another," said Glenn Zeitz, a prominent South Jersey lawyer who is not involved in the case. "They're leaving open that his death could have been a murder or a suicide. This sort of turns everything on its head."

A spokesman for the Sheridan family, Tom Wilson, declined to comment on the death certificates.

Both death certificates were filed Oct. 7 with the state Department of Health, Office of Vital Statistics and Registry, and issued by the office on Oct. 30.

The death certificates did not indicate who filed them, but typically in New Jersey they are completed jointly by a funeral director and a hospital, a physician, or a medical examiner, according to a spokeswoman for the state Department of Health. The medical examiner determines the manner of death.

Death certificates are provided to next of kin and are not public record.The Sheridans' death certificates obtained by The Inquirer were on file with the Somerset County Surrogate's Office, along with a petition by two of the Sheridans' sons seeking to serve as administrators of their parents' estates because a will had not been located. Surrogate filings are public records.

John Sheridan was a former state transportation commissioner whose role in the GOP influenced public policy.

The state Attorney General's Office has dispatched a team of its lawyers and investigators as well as detectives from the New Jersey State Police to assist with the investigation.

Authorities have released few details about the deaths or the fire, which was ruled intentionally set. The Somerset County Prosecutor's Office has repeatedly declined to respond to questions about whether the Sheridans suffered injuries beyond any caused by the fire.

The couple were found unresponsive in their second-floor master bedroom. John Sheridan was found under a large armoire, a source said. Gasoline was used to set the fire in the bedroom and a gas can, usually kept in the garage, was found in the bedroom, two sources said.

Two knives were recovered, and one was believed to have been used to inflict wounds on both Sheridans, one of the sources said. It is believed that a third weapon, which has not been recovered, caused the wounds on John Sheridan's neck and side, the source said.

Last week, a spokesman for the Medical Examiner's Office referred inquiries about the couple's death certificates to the county Prosecutor's Office.

Jack Bennett, a spokesman for the Prosecutor's Office, said in a Nov. 18 e-mail: "We have not received death certificates regarding John and Joyce Sheridan."

Bennett did not respond to requests seeking comment Tuesday. The office has previously said it is awaiting laboratory analyses and the medical examiner's determinations before announcing its findings.

The Prosecutor's Office has said it was confident that the Sheridans' four sons "played no role" in their parents' deaths and there was no danger to the public.

Records filed by an attorney for Mark and Matthew Sheridan - who filed to be the administrators - list the value of the combined estates of the parents to be slightly more than $2 million. No detailed list of assets has been filed. The couple owned property, vintage cars, and antiques.

The Sheridans' two younger sons, Tim and Dan, renounced their rights to serve as administrators, according to the Surrogate's Office records.

Hours after the fire, Matthew Sheridan, 40, was arrested at his parents' home for third-degree cocaine possession and possession of drug paraphernalia, for baggies and a digital scale found in his car, police records show. Charges against him have not been pursued by the Prosecutor's Office, which said it has up to five years to do so. Authorities said the arrest was unrelated to the fire.

The sons hired Michael Baden, a nationally known forensic pathologist, to assist in the case. Baden has testified in high-profile cases, including that of the police officer in Ferguson, Mo., who fatally shot Michael Brown, an unarmed teenager.

mburney@phillynews.com

856-779-3814 @mlburney