The body of 85-year-old James Conaway was found shortly before noon Tuesday in the driveway of his home on the 300 block of High Ridge Road in the Owls Nest Estates neighborhood.
Authorities say a relative discovered the scene and called police.
Police found Conaway lying near a Volvo SUV. He was pronounced dead at the scene.
Investigators have not yet determined a cause of death.
Investigators initially reported that Conaway's 2010 bronze Cadillac DTS was missing from the home, but it was later found.
Police learned that Conaway's daughter was using the car on Monday, and had suffered a medical emergency, which led to an accident in the parking lot of Lucky's Coffee Shop, in the 4000 block of Concord Pike.
Delaware State Police handled the accident. Detectives have not provided any details on the daughter's location. Police now have the vehicle. Neighbors who knew the man say that he had retired from DuPont and was a widower for many years.
The incident remains under investigation.