A North Dakota man is behind bars after he fatally shot his sister and 3-year-old niece and injured his mother on an Indian reservation, police say.

Johnnie Jay Gaking, 27, is charged with two counts of second-degree murder and one count of attempted murder. Fargo NBC affiliate KVLY identified the deceased victims as Gaking’s sister, 31-year-old Tiana Sharel Walking Eagle, and her 3-year-old Lokia Jay Lee Walking Eagle. According to a probable cause arrest affidavit in the U.S. District Court for the District of North Dakota, the shooting occurred at a home on the Spirit Lake Reservation near Tokio.

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Agents with the Bureau of Indian Affairs entered the home and found Walking Eagle and her daughter Lokia dead from gunshot wounds to the head. Paramedics rushed Gaking’s mother to the hospital.

Cops learned that after allegedly shooting the three, Gaking drove to another home on the reservation. Two people in the home told cops that Gaking arrived in a blue Ford Focus and came inside with “crazy eyes,” the affidavit said. He allegedly stated that his sister was “dead, they’re all dead, I didn’t do it.” Gaking had blood on his chest and abdomen from self-inflicted stab wounds, the affidavit stated.

The suspect then drove away and crashed into a ditch. Cops then took him into custody. In the ambulance on the way to the hospital, Gaking allegedly told an agent that “men in ski masks had been stalking him” and “they” made him kill his loved ones. At first, he insisted the people in ski masks stabbed him, but then admitted he was trying to commit suicide, the affidavit said.