"Evidence suggests arson/suicide," Columbia County sheriff's Capt. Steve Morris said. "It remains an open death investigation. It is premature to rule anything out, or in for that matter."
A passerby called in the fire at 997 Windmill Lane about 4:30 a.m. Martinez-Columbia Fire Rescue personnel found the body of Alexander Blake Cooper inside.
Capt. Morris said Mr. Cooper, who had previously attended Greenbrier High School, had what "appears to be a gunshot wound to the head. ... A weapon was recovered from the scene."
An autopsy performed at the Georgia Bureau of Investigation Crime Lab in Augusta determined that Mr. Cooper died of a self-inflicted gunshot wound, Columbia County Deputy Coroner Bonnie Holloway said.
Mr. Cooper's parents, with whom he shared the home, were out of state at the time.
The fire started in a front bedroom of the two-story brick home in the Windmill Plantation subdivision, said Honey Shore, a Martinez-Columbia Fire Rescue spokeswoman. Mr. Cooper's body was found in another room.
Firefighters quickly got the blaze under control and contained most of the fire damage to the front bedroom.
Martinez-Columbia fire investigators are still trying to determine the cause of the fire.
The state Fire Marshal's Office was called in to assist with the investigation, Ms. Shore said.
Reach Valerie Rowell at (706) 868-1222, ext. 110 or firstname.lastname@example.org.