The young teen accused of killing a teacher at the troubled Cheltenham juvenile detention facility pleaded guilty to murder and attempted first-degree rape Friday — as well as attempted murder in an unrelated break-in and stabbing.

Brian Wonsom made the pleas in Prince George's County Circuit Court as part of an agreement that saw him sentenced to life in prison with all but 85 years suspended. Wonsom was charged in the killing of Hannah Wheeling, 65, a teacher from Bel Air whose bludgeoned and partially clothed body was found Feb. 18, 2010, at the Cheltenham Youth Facility in Prince George's County. The Laurel youth was being held there on burglary charges.

Wonsom, 15, was being tried as an adult on the charges related to the Cheltenham attack. He was only 13 at the time of the killing.