BILLINGS, Mont. (AP) — A federal judge has sentenced a Wyoming man to life in prison for the murders of two good Samaritans who stopped to help him on Montana's Crow Indian Reservation.

U.S. District Judge Susan Watters said Thursday that 20-year-old Jesus Deniz Mendoza posed a continuing danger and was unable to control the "demons" of mental illness and drug use that that he blamed on the killings.

Mendoza pleaded guilty to shooting Jason and Tana Shane in the back of the head along a roadside near Pryor in July 2015.

He shot the couple's grown daughter as she was running from the scene and fired at several other people who sought to help the family.

His sentencing comes days after the close-knit Crow reservation was again wracked by violence with three people killed and two wounded at a house in Lodge Grass.