WASHINGTON — At the last argument of the Supreme Court’s current term, featuring what was very likely Justice Stephen G. Breyer’s last appearance on its bench, the justices on Wednesday considered the aftermath of a decision in 2020 declaring that much of eastern Oklahoma falls within Indian reservations.
The decision, McGirt v. Oklahoma, ruled that Native Americans who commit crimes on the reservations, which include much of Tulsa, cannot be prosecuted by state or local law enforcement and must instead face justice in tribal or federal courts.
The question for the court on Wednesday was whether similar limits apply to non-Indians who commit crimes against Indians on reservations. But much of the argument was devoted to debating the larger issues in and the consequences of the McGirt decision, which was decided by a 5-to-4 vote, with Justice Ruth Bader Ginsburg in the majority.
Justice Ginsburg died a few months after the ruling was issued, and her replacement by Justice Amy Coney Barrett raised the possibility that the court might move in a different direction in the new case, Oklahoma v. Castro-Huerta, No. 21-429. Justice Barrett’s questions on Wednesday did not yield conclusive evidence about her views on the McGirt decision.
The new case concerns Victor Manuel Castro-Huerta, who was convicted of severely neglecting his 5-year-old stepdaughter, an enrolled member of the Eastern Band of Cherokee Indians who has cerebral palsy and is legally blind. In 2015, she was found dehydrated, emaciated and covered in lice and excrement, weighing just 19 pounds.
Mr. Castro-Huerta, who is not an Indian, was prosecuted by state authorities, convicted in state court and sentenced to 35 years in prison.
After the McGirt decision, an Oklahoma appeals court vacated his conviction on the ground that the crime had taken place in Indian Country. The appeals court relied on earlier rulings that crimes committed on reservations by or against Indians could not be prosecuted by state authorities.
Federal prosecutors then pursued charges against Mr. Castro-Huerta. Zachary C. Schauf, one of his lawyers, told the justices that his client had entered a plea agreement calling for a seven-year sentence, adding that the standards for parole are more lenient in Oklahoma than in the federal system.
Kannon K. Shanmugam, a lawyer for Oklahoma, said that the McGirt decision had transformed the criminal justice system in the state and that federal authorities were struggling to keep up with their new workloads.
Justice Samuel A. Alito Jr., who dissented in McGirt, asked Edwin S. Kneedler, a lawyer for the federal government, whether criminal laws in Oklahoma were being adequately enforced.
“Is it a sustainable situation?” Justice Alito asked. “Is the federal government going to be able to provide enough federal agents, enough federal prosecutors, enough federal judges, enough federal courtrooms, enough federal probation officers, to handle the caseload that was previously handled by state law enforcement?”
Mr. Kneedler, who argued in favor of Mr. Castro-Huerta’s position that the state could not prosecute his case given the identity of the victim, said, “I’m not here to minimize the challenge that has resulted from the decision in McGirt.” He added that the federal government had shifted resources to the state and had asked Congress for $40 million for more prosecutors, F.B.I. agents and prison space.
Justice Neil M. Gorsuch, the author of the majority opinion in the McGirt decision, said there were good reasons to apply it to non-Indian offenders with Indian victims on reservations. For starters, he said, the Supreme Court had on some 10 occasions made statements in its decisions backing the idea.
Justice Gorsuch also cited the long history of state hostility to the interests of Native American tribes. “We have the treaties, OK, which have been in existence and promising this tribe since before the Trail of Tears that they would not be subject to state jurisdiction precisely because the states were known to be their enemies,” he said, referring to the forced relocation of some 100,000 Native Americans from their homes in the Southeast in the 1800s.
Justice Gorsuch seemed to urge his colleagues to stand behind the McGirt decision in the face of an outcry from some politicians and members of the public. “Are we to wilt today because of a social media campaign?” he asked.
Justice Brett M. Kavanaugh, who dissented in McGirt, urged an approach that would allow both federal and state prosecutions. “Indian victims right now are not being protected because the federal government doesn’t have the resources to prosecute all these crimes,” he said. “And this would not be displacing the federal government.”
At the conclusion of the argument, Chief Justice John G. Roberts Jr. congratulated Mr. Kneedler, who had just presented his 150th argument to the court. Then the chief justice turned his attention to his retiring colleague.
“The oral argument we have just concluded is the last the court will hear with Justice Breyer on the bench,” Chief Justice Roberts said, growing emotional. “For 28 years, this has been his arena for remarks profound and moving, questions challenging and insightful, and hypotheticals downright silly. This sitting alone has brought us radioactive muskrats and John the Tiger Man.”