James Yarbrough, 77, was found dead Wednesday in his home at 544 Morgan Valley Road.
“Foul play is indicated, which was confirmed by an autopsy today at the GBI Crime Lab, which determined the manner of death is homicide,” said John Bankhead, GBI spokesperson.
The GBI is assisting the Polk County Police Department in the investigation.
Bankhead said police are not releasing the cause of death because of the ongoing investigation.
The initial police report listed a 4:22 a.m. Thursday incident time, but Bankhead said Yarbrough was found around 10 p.m. Wednesday.
Bankhead said Yarbrough lived alone.
GBI investigates death of Rockmart man