NCAI and NARF Applaud Unanimous Supreme Court Decision to Uphold Tribal Law Enforcement Authority in United States v. Cooley

Published on Jun 01, 2021

Washington, DC – The National Congress of American Indians (NCAI) and the Native American Rights Fund (NARF) applaud this morning’s decision in the United States Supreme Court case United States v. Cooley (19-1414). Rightfully, the Court held that tribal law enforcement have the authority to temporarily detain and search non-Indians traveling on public rights-of-way running through a reservation for suspected violations of state or federal law.

“Protecting our tribal citizens is one of the most basic services we can provide, and today every member of the Supreme Court agreed,” said Fawn Sharp, President of the National Congress of American Indians. “This 9-0 decision is one of the strongest affirmations of tribal sovereignty in a generation and helps secure Native communities. For too long, non-Native criminals escaped justice from crimes committed on tribal lands, but today’s unanimous decision in United States v. Cooley is monumental in changing that. We applaud this decision and look forward to advocating for our member tribes as they improve safety and security in tribal communities as a result of this new precedent.”

This case involves the temporary detention and search of Mr. Cooley, a non-Indian, by a Crow Tribe police officer. After conducting a safety check of the vehicle parked on the side of a state roadway crossing the reservation, the tribal police officer formed the opinion that the motorist was non-Indian, observed firearms in the vehicle, and suspected possible violations of state or federal law. He detained the motorist while local and federal police were being dispatched. A subsequent search of the vehicle by the tribal police officer uncovered 50 grams of methamphetamine and additional firearms. The district court granted the driver’s motion to suppress evidence obtained by the tribal police officer, and the Ninth Circuit affirmed.

The Tribal Supreme Court Project, which is jointly staffed by NARF and NCAI attorneys, coordinated the preparation and filing of eight amicus briefs supporting the tribal interests in this case. NCAI joined tribal nations and inter-tribal organizations in urging the Court to reject the Ninth Circuit’s decision. NCAI’s amicus brief can be found on the Tribal Supreme Court Project’s website.

Relying on the second exception in Montana v. United States, 450 U.S. 644, 566 (1981), the Court affirmed tribal inherent sovereign authority to address “conduct [that] threatens or has some direct effect on . . . the health or welfare of the tribe.” It also reasoned that not recognizing authority to detain suspected non-Indian offenders could pose serious threats to public safety in Indian country. The Court noted that several state and lower federal courts have recognized this authority and several Supreme Court opinions assumed such authority existed. Moreover, the Court pointed out, such detentions of non-Indians do not subject them to tribal law, but only to applicable state or federal law.

The Court vacated the Ninth Circuit’s decision and remanded the case for further proceedings. Read today’s opinion here.  


About the Native American Rights Fund:

Founded in 1970, NARF is the oldest and largest non-profit dedicated to asserting and defending the rights of Indian tribes, tribal organizations, and individual Indians nationwide. For the past 48 years, NARF has represented over 275 Tribes in 31 states in such areas as tribal jurisdiction, federal recognition, land claims, hunting and fishing rights, religious liberties, and voting rights. For more information, visit

About the National Congress of American Indians:

Founded in 1944, the National Congress of American Indians is the oldest, largest and most representative American Indian and Alaska Native organization in the country. NCAI advocates on behalf of tribal governments and communities, promoting strong tribal-federal government-to-government policies, and promoting a better understanding among the general public regarding American Indian and Alaska Native governments, people and rights. For more information, visit


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