Former Alexandria sheriff James H. Dunning died early Thursday morning in Hilton Head, S.C., according to South Carolina authorities and Alexandria police.

Dunning, 62, appeared to have died in his sleep, Alexandria police spokesman Jody Donaldson said. The Beaufort County (S.C.) Coroner’s Office has ordered an autopsy to determine the cause of death, authorities said.

A preliminary autopsy should be completed within a few days, said Sgt. Robin McIntosh, a spokeswoman for the Beaufort County Sheriff’s Office.

“There doesn’t appear to be anything suspicious at this time,” McIntosh said.

Dunning retired to Hilton Head several years after the high-profile 2003 killing of his wife, Nancy Dunning, in the couple’s Alexandria home.

Nancy Dunning, a successful real estate agent, was known as the “Queen of Del Ray” because of her devotion to her neighborhood. Her body was found by her husband and son near the front door of the family home.

The case has not been solved. A group of Nancy Dunning’s friends started a reward fund and erected a stark white billboard in the heart of Del Ray asking, “Do you know who killed Nancy Dunning?”

Police at the time said they thought she was targeted by someone she knew.

Alexandria police said Thursday that the case is still an active investigation, and they urged anyone with information about the killing to call them.

James Dunning was elected sheriff in 1985 and served for two decades. He was known for running an efficient and secure jail.

During his career, he was responsible for overseeing such high-profile inmates as convicted spies Robert P. Hanssen and Brian P. Regan. Terror suspect Zacarias Moussaoui was also housed in the Alexandria jail, as was John Walker Lindh, a U.S. citizen who was captured in Afghanistan while fighting with the Taliban.