Elbert White heard gunshots Saturday and stepped outside to investigate.
Two doors down from his mother's house on Sterling Street, a man ran outside and collapsed under a tree. Another man wearing a maroon shirt running in the opposite direction passed directly in front of White.
White started to shout before the running man pointed a gun at him.
"All I saw was a big old gun," said White, when asked for a description of the gunman.
White ducked behind a car in the driveway and watched as the gunman, who was carrying a black bag, ran out of sight behind a house.
Deputies and then an ambulance pulled into the cul-de-sac in the 300 block of Sterling Street about 4 p.m.
Neighbors said medics worked frantically on the victim, Roderick Tolbert, 47, who later died.
Richmond County Sheriff's Sgt. James Kelly would not release any more information on the homicide Saturday evening.
It was Richmond County's 31st homicide of the year.
The 30th happened on Wednesday when a teenager driving his car about 2 a.m. on Dewitt Street was shot in the head. Terrence Lamont Turner Jr., 16, crashed his car into a fence and was taken to Medical College of Georgia Hospital, where he died.