Authorities were still working Thursday to determine whether to charge a man who they believe fatally shot his son at their Hiwassee home this week.

Steven Matthew Duncan, 24, died Tuesday after being shot once with a handgun, Pulaski County Sheriff Jim Davis said.

His father, 69-year-old Graham Puckett Duncan, is being investigated in connection with the incident, Davis said. No charges have been filed and Graham Duncan is not in police custody, Davis said.

Deputies have conducted several interviews and those are in the process of being transcribed, said Pulaski County Commonwealth's Attorney Mike Fleenor, who will determine whether anyone will face charges. He said it could take some time to sort out the case.

"We're looking at a lot of issues, self-defense being one of them," Fleenor said.

Fleenor said investigators are also waiting on a toxicology report from the medical examiner's office that will show whether Steven Duncan was intoxicated.

A preliminary autopsy report showed that Steven Duncan died of a single gunshot wound to the chest, Fleenor said.

A family member reached by telephone Thursday declined to talk about the incident.

It happened about 4:30 p.m. at Graham Duncan's home on Duncan Hill Lane, Davis said. He said Steven Duncan lived with his father "most of the time."

Minutes before getting a call that someone had been shot, Davis said, the sheriff's office received a call from a neighbor who reported being involved in a separate altercation at the same house.

Davis would not say if either Steven Duncan or Graham Duncan was reportedly involved in that altercation.

Records from Pulaski County General District Court show that Steven Duncan had been convicted twice of possessing marijuana, a misdemeanor, once in June and once in August. In October he was convicted of possessing a controlled substance, also a misdemeanor.