POLSON, Mont. -

 A 17-year-old Arlee boy has pleaded guilty to stabbing his stepfather to death and critically injuring his mother last November.
KERR-AM reports Nathan Butler pleaded guilty Wednesday in District Court in Polson to deliberate homicide in the death of 51-year-old John Fisher. He pleaded guilty to attempted deliberate homicide for a stabbing that critically injured his mother, Dacia Vollin and to assault with a weapon for stabbing another man in the chest.
Prosecutors say Butler told investigators he had been waiting in his room with a knife with plans to stab his mother. When Fisher responded to her calls for help, Butler said he stabbed him.
The plea agreement calls for a joint recommendation of 80 years in prison.
Sentencing is set for September.