Kyle Willis hadn’t seen Kimberly Graham in years, since the day she was sentenced to 107 years in prison after she drunkenly plowed her truck into a group of motorcyclists in Tulsa, killing five people, including his mother and stepfather.

So it was a shock when he saw her at a court hearing last month — tanned, dressed in a frilly purple top and jeans and laughing — a free woman. Graham, who is Native American, was let out of prison in April after a Supreme Court decision last year that found that a large part of eastern Oklahoma is still Indian country. Despite a century of state and local prosecutions, the court ruled that crimes there were the province of federal and tribal courts.

“She’s enjoying life as if nothing ever happened,” said Willis, 34, of Broken Arrow, Okla., who said the sight of Graham left him numb. “It’s bizarre. It’s crazy.”

The Supreme Court’s landmark decision in McGirt v. Oklahoma said prosecution of Native Americans for crimes in the expanded Indian country must be carried out in federal and tribal courts, rather than by state or local officials. It was celebrated across the country by Native Americans last July, who saw it as a historic affirmation of treaties signed with the U.S. government in the 1800s.

But in the year since, the ruling has upended Oklahoma’s criminal justice system, imperiled convictions in thousands of cases, sowed confusion for police and emergency responders and led to the direct release of more than 50 criminals convicted on charges including second-degree murder and child abuse, state records show.

And there may be wider impacts for the region, which covers 19 million acres in eastern Oklahoma, includes a portion of the state’s second-biggest city, Tulsa, and is home to 1.8 million people.

A local power plant is challenging an increase in its property taxes. The state is fending off a move by the federal government to strip its ability to regulate mines on Indian land. The state has also raised concerns about a potential loss of tax revenue.

The fallout has exacerbated long-standing tensions between Oklahoma’s Republican governor, Kevin Stitt, who is a citizen of the Cherokee Nation, and the leaders of five tribes involved. Stitt held a community forum on the issue this month that degenerated into raucous shouting, with attendees booing and chanting, “Treaties are the law of the land!”

“We are living a nightmare out here,” said Ryan Leonard, the Oklahoma governor’s special counsel for Native American affairs. “It’s complete, dysfunctional chaos in the state of Oklahoma.”

Leaders of the tribes have pushed back against Stitt, saying that the state stoked fear by alleging that criminals are being released and that state officials have overestimated the number of cases that may have to be revisited — about 79,000, by the state’s count.

“People see McGirt as this drastic change in the law, but the tribes don’t see it that way,” said Sara Hill, the attorney general of the Cherokee Nation. “They see it as affirming and restoring authority to the tribes.”

The Oklahoma Department of Corrections says that courts have dismissed or vacated convictions in 129 cases because of McGirt. The total includes at least 57 people who were released after being earlier convicted of crimes including child abuse, robbery, manslaughter, second-degree murder, shooting with intent to kill, lewd acts with a child and burglary.

With the state forced to step back, the tribes have expanded their legal operations, adding new prosecutors, marshals and victims services coordinators. The Cherokee Nation, for example, has added six prosecutors, two district court judges and 13 marshals in recent months, filing 1,300 cases this year.

The Cherokees support proposed federal legislation introduced by U.S. Rep. Tom Cole (R-Okla.) that would allow them, as well as the Chickasaw Nation, to forge an agreement with the state to resolve jurisdictional issues.

But other tribal leaders are loath to make any concessions after the ruling affirmed the binding nature of commitments made to their forebears generations ago.

“The McGirt decision has created so many opportunities for improved safety and security for all citizens of Oklahoma,” David Hill, the principal chief of the Muscogee Creek Nation, said in a statement. “We have continually sought collaboration with state and local officials to realize this new promise. But rather than work together, some politicians seem determined to return to the broken system of the past.”

Supreme Court Justice Neil M. Gorsuch invoked the nation’s troubled past when he cast the deciding vote in McGirt last summer. The ruling came after lawyers for a convicted child molester, Jimcy McGirt, argued that the state did not have jurisdiction to prosecute him because he was a Native American on tribal land.

“On the far end of the Trail of Tears was a promise,” Gorsuch wrote, alluding to the forced relocation of the Cherokee, Choctaw, Chickasaw, Creek and Seminole nations in the 1800s. “Forced to leave their ancestral lands in Georgia and Alabama, the Creek Nation received assurances that their new lands in the West would be secure forever.”

He concluded: “Because Congress has not said otherwise, we hold the government to its word.”

Gorsuch said the objections by Oklahoma and the federal government that such a finding would throw law enforcement in the area into chaos were not enough: “Dire warnings are just that, and not a license for us to disregard the law.”

Gorsuch, the only member of the Supreme Court to have served on a federal appeals court in the West, has been a strong vote for Native American interests on the court. Although a consistent conservative, he sided in McGirt v. Oklahoma with the court’s then-four liberals, including Justice Ruth Bader Ginsburg, who died in September.

However, Chief Justice John G. Roberts Jr. warned in his dissent that “the State’s ability to prosecute serious crimes will be hobbled and decades of past convictions could well be thrown out. On top of that, the court has profoundly destabilized the governance of eastern Oklahoma.”

This spring, Oklahoma filed an emergency application with the Supreme Court and said Roberts’s prediction had been prescient.

In applying the McGirt decision, the Oklahoma Court of Criminal Appeals threw out the state conviction of a man convicted of murder in the killing of a Native American woman and her two children in what is now considered Indian country and opened the door for others to contest their convictions.

The federal government intends to retry Shaun Michael Bosse and others convicted in the most serious cases, including inmates on death row. Those prisoners are unlikely now to face the death penalty, the U.S. attorney’s office said. According to federal law, tribes have to opt in for the death penalty, and none of the five tribes has done so.

The U.S. attorney’s office for the Northern District of Oklahoma said it had reviewed 2,460 cases by mid-July, accepting 826 for prosecution and referring approximately 1,474 to tribal prosecutors. It has had to expand its staff by more than 58 percent as caseloads have doubled.

But not all cases will head back to court, and then-Oklahoma Attorney General Mike Hunter told the Supreme Court that significant numbers of convicts would be released.

“It appears likely that 27% of convicts who raise McGirt postconviction claims have a good chance of going free without re-prosecution by the federal government,” Hunter said in the emergency application this year. “Given the hundreds of post-conviction cases now accumulating in district courts, the public safety considerations are frightening.”

Hunter asked the justices to put the state court’s ruling on hold while the state prepared for another try at the Supreme Court, and the court agreed, without explaining its reasoning. The court’s three liberals dissented.

The court’s willingness to grant the stay on Bosse’s case may indicate that some of the justices are willing to reexamine or limit the McGirt ruling, analysts said. The court’s balance on the issue has shifted, with the liberal Ginsburg replaced by conservative Amy Coney Barrett. The state is preparing a formal petition to the court to accept the case for additional briefing and oral arguments.

The court’s stay in the Bosse case has granted the state some breathing room, but law enforcement officials and emergency responders say the ruling continues to cause complications.

Charlie D. Peoples, an emergency response dispatcher, said the McGirt ruling has meant that he is now required to ask 911 callers if they are members of a federally recognized tribe. If they are, he transfers the callers to the Muscogee Creek Nation, where they are “sometimes met with a hold tone and music because the call volume is so high,” he said

Law enforcement officers responding to a scene have seen tribal license plates on cars, then spent time sorting out who was Native American and who wasn’t, Peoples said.

“The rules are very unclear, and we have no formal training,” he said in an interview. “It’s very confusing, and it’s very taxing on all first responders, honestly.”

In recent weeks, family members of victims like Willis have organized protests as they grapple with fresh wounds from traumatic chapters of their lives they believed were closed or at least finally adjudicated long ago.

“We are retraumatizing victims at a perilous rate. That is not anywhere close to justice,” said Steve Kunzweiler, the district attorney for Tulsa County.

Federal and tribal prosecutors will have to retry some cases for which key witnesses have died, memories have faded and evidence has been lost. Tribal courts can sentence up to a maximum of three years per count and can order those sentences to be served concurrently, for up to nine years in some instances.

Tessa Williams, 50, of Owasso, is steeling herself for the federal retrial of Clarence Rozell Goode Jr., who was given the death penalty after he was convicted of killing her sister, brother-in-law and 10-year-old niece Kayla with two accomplices during a family dispute in 2005. A lead detective in the case has died, along with several witnesses, including Williams’s mother, who found the bodies when she stopped by the home to give Kayla her cheerleading uniform.

“Some days I don’t even remember why I go into the kitchen, but I can tell you every detail of what happened then, the things you heard and what was done in that courtroom,” Williams said. “I don’t want to see it again; I don’t want to hear it again.”

But, Williams said, “there’s nothing we can do about it but stay strong and do our part and make sure justice is carried out.”

Graham, the woman who was released in April, was convicted in 2008 on five counts of manslaughter and leaving the scene of an accident after she allegedly drank alcohol and drove her truck into a group of people, including Willis’s mother, DeAnna Rosser-Coatney, a fourth-grade teacher. A witness later testified that Graham left an “explosion of bodies” in her wake as she left the scene.

Federal prosecutors cannot retry the case because of a five-year statute of limitations on manslaughter. The tribal court has a limit of seven years. But after family members, including Willis, waged an extensive campaign of telephone calls, emails and TikTok videos, prosecutors for the Creek Nation agreed to take up the case. They argued in filings that the statute of limitations should be suspended because of the unusual circumstances of the McGirt decision. Graham is free on a $52,000 cash bond.

Her lawyer, Richard 0’Carroll, said she did not want to give an interview.

“She’s moving on with her life,” he said.

He said she was unlikely ever to spend another night in jail in the case.