Desmond Grissam, 18, has pleaded not guilty in Richmond County Superior Court.
He is accused of joining Tavaris Wilcher, 21, in a plot to lure 29-year-old Tollie Mitchell into a drug sale so they could rob him.
Mr. Mitchell was fatally shot in the neck in the process, sheriff's investigators think.
Mr. Mitchell's body was found in his Honda Accord the afternoon of May 11, 2007. The car was at Regency Square Apartments behind Regency Mall.
Mr. Wilcher was tried and convicted of murder and weapons violations in March 2008. He is serving a sentence of life plus five years in prison.
Mr. Mitchell had two previous convictions for drugs.
In 1999 he was sentenced to 10 years on probation for possession of cocaine, and in 2002 he was sentenced to 15 years in prison for possession of marijuana with intent to sell.
Mr. Mitchell was paroled in January 2007.
He had been a victim of violence in the past. In November 1997, Quinton D. Hughes shot Mr. Mitchell three times.
Mr. Hughes spent nine years in prison for aggravated assault before he was released on parole in November 2007.
Reach Sandy Hodson at (706) 823-3226 or firstname.lastname@example.org.