BILLINGS, Mont. (AP) — A Big Horn County commissioner says the search for a suspect in a triple shooting on the Crow Reservation is spanning the southeast Montana countryside as people are warned to stay inside for their safety.

Authorities were searching Wednesday for 22-year-old Sheldon Bernard Chase in the deaths of an elderly woman and a young couple at a rural residence southeast of Lodge Grass.

Commissioner John Pretty On Top says Lodge Grass schools have re-opened but classes are being held behind locked doors.

Chase has a history of mental illness and is considered armed and dangerous. He is described as 6 feet, 2 inches tall with brown hair and weighing 230 pounds. He may be driving a Toyota Corolla or Celica with South Dakota license plates or a 2000 red Volkswagen Jetta.