Johnson was 53-year-old when he got a mandatory life sentence in 2008 after he was found guilty of sexual assault on an 8-year-old girl
He was imprisoned at Santa Rosa Correctional Institution in Milton, Florida when an undisclosed illness killed him.
Johnson, who was a third-round pick from Auburn by the Hawks in the 1977 NBA draft, became an immediate contributor and then starter for the Hawks.
Averaged 15.1 points in 10 NBA seasons, Johnson received a lifetime suspension from the NBA in 1987 for his cocaine use.
His death was confirmed by Rocker-Cusack Mortuary in Leesburg, Florida.
The mortuary announced that Johnson will be buried at Weirsdale (Florida) Community Cemetery on Saturday.
Source: TheWill 2020