Sims, 27, pleaded guilty Thursday to the six slayings and was sentenced to six life terms plus another 240 years, but will be spared the death penalty.
Sims pleaded guilty to beating, shooting and robbing the victims, who had been asleep inside a mobile home. His co-defendant, Jaime Underwood, pleaded guilty two years ago and was sentenced to 120 years in prison.
Tift County District Attorney Paul Bowden said the plea agreement would keep Sims locked up past his 99th birthday ensured "certainty and finality as well as punishment of the defendant and the protection for society."
The Atlanta Journal-Constitution said Sunday that Sims had repeatedly changed attorneys while awaiting a potential death-penalty trial, which Bowden said contributed to his decision to accept a plea that would take execution off the table.