Former Alexandria Sheriff James Dunning died early Thursday morning in Hilton Head, according to Alexandria police.

Dunning, 62, appeared to have died in his sleep, said Alexandria Police spokesman Jody Donaldson. The local medical examiner’s office will perform an autopsy and determine a preliminary cause of death in the next few days, police said.

Alexandria police were informed of Dunning’s death by the Beaufort County Sheriff’s Office in South Carolina.

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

Nancy Dunning was a successful real estate agent known as the “Queen of Del Ray” for her devotion to her neighborhood.

The case was never solved. It attracted so much attention that a group of her 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 believe she was targeted by someone she knew.

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

James Dunning, who served as the city’s sheriff for two decades, 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, who was captured in Afghanistan while fighting with the Taliban.

This item has been updated.