Kelli O'Laughlin, 14, was stabbed to death at her home in October of 2011.
Investigators said John Wilson, Jr., killed her during a botched robbery, then sent taunting text messages to her parents.
He was convicted of her murder and sentenced to 160 years behind bars.
Corrections officials say he died Tuesday. The cause of death has not been released.
O'Lauglin's mother wrote on Facebook, "The day has come for Kelli Joy to rest in peace."