BILLINGS, Mont. (AP) — A 19-year-old Wyoming man is set to plead guilty to a double-murder on Montana's Crow Reservation under an agreement with federal prosecutors that would send him to prison for life.

Jesus Deniz Mendoza was scheduled to appear at a Tuesday hearing before U.S. District Judge Susan Watters in Billings.

The Worland man agreed to plead guilty to two counts of second degree murder, assault with intent to commit murder, three counts of using a firearm in a violent crime and assault with a dangerous weapon.

He was charged with killing Jason and Tana Shane and wounding their daughter after the family stopped to help him on a roadside near Pryor in July 2015.

Prosecutors say Mendoza later returned to the scene and shot at three people who'd responded to the attack.