The U.S. Supreme Court has agreed to hear the appeal of a Navajo man who claims that the charges he faced in the tribal and federal justice systems for a single crime in Colorado violated double jeopardy.

On Oct. 18 the nation’s highest court granted a petition from Merle Denezpi, who is asking the justices to decide whether the Court of Indian Offenses of the Ute Mountain Ute Agency in southwestern Colorado is an arm of the federal government. If so, the constitutional prohibition against double jeopardy should have barred his second prosecution by the U.S. government after the Court of Indian Offenses sentenced him for his offense.

Denezpi traveled from Arizona to the Ute Mountain Ute reservation in July 2017 with his victim, both of whom were Navajo. At his girlfriend’s house near the town of Towaoc, Denezpi threatened and sexually assaulted the victim. She escaped and reported the crime to police, also undergoing a forensic examination.

Denezpi faced an assault charge in the Court of Indian Offenses of the Ute Mountain Ute Agency. The judicial entity is a “CFR court,” named for the Code of Federal Regulations. Congress created CFR courts to enable tribes to exercise jurisdiction over American Indians if no tribal court has been set up. There are approximately 400 tribal justice systems in the United States — only five of which are regional CFR courts.

Denezpi offered a plea to assault and battery in violation of tribal law and served a sentence of 140 days in custody.

But six months later, a federal grand jury indicted Denezpi for aggravated sexual abuse in Indian Country. Both federal and tribal jurisdiction kicked in because the victim and perpetrator in Denezpi’s case were Indian. After his conviction, Denezpi received a sentence of 30 years in prison.

Upon appeal, the U.S. Court of Appeals for the 10th Circuit determined the doctrine of dual sovereignty applied. In instances where an offense is against the laws of two sovereign entities — the federal government and tribal nations — there is no prohibition on a prosecution by each entity. Given that the tribe inherently had sovereignty and Congress’s creation of the CFR court had not taken away the tribe’s self-governing power, the 10th Circuit found no double jeopardy violation from Denezpi’s conviction.

The appeals court relied on the 1978 case of United States v. Wheeler, in which the Supreme Court confirmed that a tribe’s power to punish violations of its law by tribal members is inherent to Indian nations’ sovereignty. However, the Wheeler decision involved a defendant prosecuted first in a tribal court and then in a federal court, leaving unanswered whether double jeopardy applies differently to CFR courts. Denezpi argues that it does.

“Like federal district courts and unlike tribal courts, CFR courts are a blend of federal and tribal prosecutorial power,” New Mexico attorney Theresa M. Duncan wrote to the Supreme Court in Denezpi’s petition. “Thus, a district court prosecution of an Indian Country offense shares the same sources of prosecutorial power as a prosecution in a CFR court.”

The federal government countered that CFR courts simply help tribes exercise their own power in the absence of a tribal court. Because tribal law also established Denezpi’s offense, the tribe could prosecute him independently of the U.S. government.

“[T]he regulations governing the Court of Indian Offenses merely regulate the use of such a court; they do not create the power to punish violations of the Ute Mountain Ute Code,” the office of then-acting Solicitor General Elizabeth B. Prelogar wrote to the court.

The Supreme Court addressed the question of tribal sovereignty in the early 1800s, with Chief Justice John Marshall writing that tribes were distinct entities fully dependent on the United States. “They look to our Government for protection; rely upon its kindness and its power,” Marshall argued, “and address the President as their Great Father.” Nonetheless, he acknowledged their inherent sovereignty. Later, the court determined states could not pass laws regulating tribes as sovereign nations, a decision that President Andrew Jackson declined to enforce.

Most recently, in a 5-4 decision last year, the Supreme Court ruled against the state of Oklahoma in deciding the state had no jurisdiction over certain cases involving American Indian perpetrators or victims in the historic Muscogee (Creek) Reservation, which now includes most of Tulsa.

The Oklahoma state attorney general has called on the court to reverse or limit the reach of Mcgirt v. Oklahoma, saying, “Some theories sound good in concept but don’t work in the real world.”