The Supreme Court unanimously ruled Tuesday that tribal police have authority to stop and detain non-Indians if they suspect a threat to the health or welfare of the tribe.
“To deny a tribal police officer authority to search and detain for a reasonable time any person he or she believes may commit or has committed a crime would make it difficult for tribes to protect themselves against ongoing threats,” Justice Stephen G. Breyer wrote for the court in the 9-0 ruling.
“Such threats may be posed by, for instance, non-Indian drunk drivers, transporters of contraband, or other criminal offenders operating on roads within the boundaries of a tribal reservation,” Justice Breyer added.
Joshua James Cooley was parked along a federal highway in Montana in 2016, when Crow Police Department Officer James Saylor saw the truck and stopped to help.
Officer Saylor noted that Cooley’s eyes were bloodshot and he had firearms in the vehicle.
The officer called for backup, including an officer from the federal Bureau of Indian Affairs. They later found methamphetamine in the truck.
A federal grand jury indicted Cooley on gun and drug offenses in 2016, but he moved to suppress the evidence, arguing that the Crow Police Department lacked authority to investigate him as a non-Indian on a public right-of-way through the reservation.
The lower courts ruled in favor of Cooley, but the government took the case to the Supreme Court and overturned a ruling by the U.S. Court of Appeals for the 9th Circuit.
The appellate court had held that the police officer should have asked Cooley if he was an American Indian before conducting an investigation.
But the high court in its ruling on Tuesday said that standard could “produce an incentive to lie” about American Indian status.