Perry Ross Schiro, 22, was sentenced to 120 to 249 months in prison.
He was the last of five suspects charged in the death of Emily Elizabeth Haddock to be convicted and sentenced.
Haddock was killed on Sept. 21, 2007, when several men broke into her home in Vass. She had stayed home from school with strep throat, and the burglars were surprised to find her inside, prosecutors said.
She was shot several times with a 22-caliber handgun, authorities said. Her grandfather found her body when he stopped by the home to check on her.
Michael Graham Currie, 21, pleaded guilty in August to first-degree murder and breaking and entering in the case and was sentenced to life in prison without the possibility of parole.
Prosecutors said Schiro hid the murder weapon in the trunk of his car.
Van Roger Smith Jr., Sherrod Nicholas Harrison and Ryan Jermar White all pleaded guilty last year to accessory charges in the case and were sentenced to prison.