Lloyd Jones is likely to spend the rest of his life behind bars, KFSM-TV in Fort Smith, Ark., reported. He entered a guilty plea to first-degree murder in the slaying of Angela Allen, 16, of Van Buren and was sentenced to at least 60 years in prison.
Jones, 36, had been paroled in 2008 after being sentenced to 10 years in prison for raping a woman at knife point.
Members of Allen's family and supporters packed the courtroom wearing buttons that said "Justice 4 Angie."
"Why did you have to kill her?" Angela's grandmother asked during the hearing, telling Jones she has forgiven him.
Angela told her family she was going out for a walk Feb. 10 and met Jones in what are known as the "Mud Town Bottoms" near the Arkansas River. Her body was later found in a barrel on property belonging to the Jones family.
Investigators said the teenager was strangled. Jones told the court he became angry when she told him she was 16 and struck out at her, knocking her into the river.