Moses J. Moseley's cause of death could not be determined.
The actor - best known for his role as zombie Mike in 'The Walking Dead' - was found dead in January at the age of 31 in the Hudson Bridge area of Stockbridge, Georgia, and although his death certificate confirmed he shot himself, the document stated the intent behind the fatal gunshot is unknown, TMZ reports.
Police in Georgia had been investigating Moses' death as a possible suicide but his family previously expressed their belief he had been kidnapped and murdered.
And last month, local police captain Randy Lee said: "During the preliminary investigation, the potential of the death being a suicide was considered while not ruling out any other possibilities.
"As investigators progressed their investigation and more evidence was processed, reviewed and analyzed, other possibilities have presented themselves including accidental.
A family member explained investigators had cited to evidence of blood splatter, the way the bullet entered Moses' skull and his hold on the gun as not necessarily indicating suicide.
Typically, people who shoot themselves put the gun to their temple or in their mouth, but it had entered below the actor's eye and never left his skull, and he had a "loose" grip on the gun, suggesting someone else may have put it in his hand.
Despite the findings in the death certificate, Moses' family still believe he was murdered.
Meanwhile, the 'Attack of the Southern Fried Zombies' actor's sister, Teerea Kimbro revealed the family received a letter of condolences from President Joe Biden earlier this week.
Teerea was unsure how the president heard about the tragedy but she believes her late brother had visited the White House in the past.