OKLAHOMA CITY — Federal prosecutors are scrambling to prevent the release of hundreds of inmates who have had their state convictions overturned in recent months following a landmark U.S. Supreme Court ruling.

Doug Horn, the senior litigation counsel with the U.S. Attorney’s Office for the Eastern District of Oklahoma, said FBI agents combing through district attorney case files estimate as many as 4,000 cases could be appealed under last year’s McGirt ruling.

In a 5-4 decision, the U.S. Supreme Court ruled that large swaths of eastern Oklahoma — in particular, the Muscogee (Creek) Nation lands — fall within Native American reservations.

Prosecutors said the ruling has altered criminal justice proceedings across eastern Oklahoma because crimes on reservation land involving defendants or victims who are tribal citizens must be prosecuted in federal or tribal courts. Those already convicted of crimes on Oklahoma’s reservation lands, meanwhile, are appealing their convictions and having them vacated on the grounds that the state of Oklahoma didn’t have the jurisdiction to prosecute them.

Horn said federal prosecutors expect the McGirt ruling to impact the state’s Five Civilized Tribes — the Cherokee, Choctaw, Chickasaw, Creek and Seminole — and said tribes in other states are also arguing the ruling applies to them.

As of mid-March, Horn said federal prosecutors have already refiled 361 cases involving crimes on Creek lands. Those included 69 murders and two manslaughters.

He said his office, which six months ago had eight criminal prosecutors, does not have enough resources to handle the growing caseload. They’ve been able to handle it thus far by having volunteers come in from across the country and by bringing people in on detail to help with some prosecutions. They’ve also requested more resources from Washington, D.C.

“Resources are a huge problem,” Horn said. “We’re working on it. The FBI has brought in dozens and dozens of agents from across the country. They bring them in on usually three-month assignments, and they’re rotating them in and out.”

He said the FBI agents are reviewing cases to determine which ones can be re-prosecuted and what evidence still exists.

When prosecutors recently reviewed a murder case from 1994, he said they discovered witnesses have died or their memory of the crime isn’t as sharp as it was nearly three decades ago.

Federal prosecutors are also finding their hands tied when it comes to re-prosecuting some violent and nonviolent offenses that have shorter statutes of limitations.

Horn said prosecutors haven’t been able to prosecute suspects who committed shootings or rapes because the federal statute that limits the time a case can be filed has expired.

“I don’t think that (the U.S. Supreme Court) realized the magnitude of this decision, and how it affects criminal jurisdiction in eastern Oklahoma, and now it’s going to probably extend to other states and other tribes,” said Orvil Loge, Muskogee County district attorney. His county sits on both Creek and Cherokee reservation lands.

Loge said he has been trying recently to prosecute a serial rape case from nearly three decades ago.

He said authorities were able to use DNA to solve the rapes of five women in Muskogee, but he was forced to dismiss the criminal case because the suspect produced proof that he was a member of a federally recognized tribe. All the offenses also occurred on Creek reservation land.

Federal prosecutors also attempted to charge the man, but their case was dismissed because the statute of limitations had passed, Loge said.

The Creek Nation declined to prosecute the case because the crimes occurred in the 1990s, and the suspect didn’t become a tribal citizen until 2013, Loge said.

Loge said he has since refiled four rape counts, arguing McGirt doesn’t apply because the suspect was not a Creek citizen at the time of the offense. He said he couldn’t refile the fifth charge because the victim was Native American.

Loge said he’s also currently prosecuting a manslaughter case involving a defendant who hit a vehicle with three people inside. One person died and two others were severely injured.

Because two of the three victims are Indian, Loge said he has had to dismiss two counts and refer those to federal prosecutors. He’ll prosecute the third count.

To date, Loge said he’s had nearly 500 cases — both old and new — impacted by the McGirt ruling.

“I think that there are some defendants that are waiting to file their McGirt motions until they know that their federal statute (of limitations) has run so that they can’t be re-prosecuted,” he said.

In a statement, Oklahoma Attorney General Mike Hunter called on Congress to act.

“Although we anticipate these individuals to still be accountable for their crimes on the federal level, our hearts go out to the victims in these cases,” Hunter said. “They are the ones who are going to have to re-live the trauma of another trial. That is why we continue to encourage Congress to pass federal legislation to allow us to compact with the tribes on criminal matters so we can share jurisdiction as we have in the past.”

Horn, the federal prosecutor, also said a solution needs to be reached.

“Nobody likes dealing with uncertainty,” Horn said. “And we are certainly dealing with a tremendous amount of uncertainty right now in not only handling these cases, but also then realizing that if a legislative fix comes, then the rules change completely again.”

Horn said the sooner state, federal and tribal leaders can come up with some sort of certainty, everybody within the criminal justice system — including the victims — will be better served.

Janelle Stecklein covers the Oklahoma Statehouse for CNHI's newspapers and websites. Reach her at jstecklein@cnhi.com.