The Effingham County Sheriff’s Office has ruled the death of a man whose remains were found earlier this year as a homicide.

The Georgia Bureau of Investigation’s state crime lab delivered its autopsy results to the ECSO on Monday and said Robert Mack’s death was the result of unspecified trauma to the body.

Mack was reported missing in September 2005. His remains were located March 8, after an anonymous tip, in the edge of a field on Ardmore-Oaky Road.

“ECSO investigators have followed leads and have been working on the case for the past five years since the disappearance,” said Sheriff Jimmy McDuffie.

Jackie Thorne has been declared a person of interest in the case since Mack was reported missing nearly five years ago. Thorne is currently serving 20-year sentences for armed robbery and aggravated assault at Smith State Prison. His sentence began April 6 and he could be in prison until May 15, 2034.

McDuffie said the case remains under investigation and the sheriff’s office will consult with the district attorney’s office on the autopsy findings.

The autopsy was conducted by a forensic archaeologist.