Investigators with the Somerset County Prosecutor's Office determined that the fire was intentionally set in the master bedroom of the Montgomery Township home where John Sheridan, 72, lived with his 69-year-old wife, Joyce. However, they did not provide further details on their findings.
Authorities have not yet said what caused the couple's deaths. County Prosecutor Geoffrey Soriano said the investigation is ongoing, adding that his office is awaiting lab test results.
Police and firefighters responded to the couple's home just before 6:15 a.m. Sunday. Authorities have said the fire was contained to the master bedroom, where firefighters found the unresponsive couple.
John Sheridan was pronounced dead at the scene.
His wife was taken to a hospital, where she died a short time later.
John Sheridan was president and CEO of Camden-based Cooper University Health Care.
In a joint statement issued Wednesday afternoon, the couple's four sons said their parents' death has left a "hole" in their hearts.
"We cannot fathom, much less explain, the circumstances of their passing," the statement said. "Losing a parent is painful. Losing them both has been excruciating and we ask everyone to respect our need to privately grieve, process our loss, and support each other as the family our parents raised us to be."
John Sheridan joined Cooper in 2005 after a long career in state government.
He was New Jersey's transportation commissioner in the administration of Gov. Tom Kean and worked on the transition team of Gov. Christine Todd Whitman. He also served as a deputy attorney general and was a general counsel for the New Jersey Turnpike Authority earlier in his career.
Anyone with information is asked to contact the Somerset County Prosecutor's Office Major Crimes Unit at (908) 231-7100, the Montgomery Township Police Department at (908) 359-3222, or the Somerset County Crime Stoppers' Tip Line at 1-888-577-TIPS (8477).