The Supreme Court unanimously ruled Tuesday that a tribal police officer can temporarily detain and search non-Natives on public rights of way that go through tribal land.

The case, United States v. Cooley, involved Joshua James Cooley, a non-Native man parked on the side of Highway 212 that runs through the Crow Reservation in southeastern Montana. Crow tribal police officer James Saylor approached the truck and found “watery, bloodshot eyes” and two guns lying on the front seat of the vehicle.