OKLAHOMA CITY (AP) — The Oklahoma man at the center of a landmark U.S. Supreme Court ruling on tribal sovereignty has reached a plea agreement with federal prosecutors less than a week before he was to go to trial, according to court documents.

Jimcy McGirt, 75, pleaded guilty Tuesday before a federal magistrate in U.S. District Court in Muskogee to one count of aggravated sexual abuse in Indian Country in exchange for a 30-year prison sentence with credit for time served.

McGirt has served more than 26 years in prison since his initial conviction in state court.

McGirt said in the signed document that he entered the plea “because I am guilty and do not believe I am innocent, I wish to plead guilty.”

U.S. Attorney Christopher Wilson said in a statement that the federal judge would still need to approve the plea deal following a presentence investigation by the court.

“McGirt will remain in the custody of the United States Marshal until the sentencing hearing, at which time the court will determine whether to accept the plea agreement,” according to Wilson’s statement.

A sentencing hearing date hasn’t been scheduled.

Defense attorney Richard O’Carroll said Wednesday that prosecutors came to them with the proposal.

“They just came with an offer and it made sense to avoid the risk” of a trial in which McGirt could be sentenced to life in prison, O’Carroll said.

Wilson didn’t immediately respond to a phone message seeking comment.

According to the plea agreement, the deal was offered for reasons including McGirt’s acceptance of responsibility for the crime, the age of witnesses and the impact that testifying might have on them.

O’Carroll said he believes McGirt has earned enough so-called good time credit for time served in state prison that he would be freed as soon as the judge accepts the plea, if the judge does so.

Although the plea was entered before a magistrate, O’Carroll said the federal judge overseeing the case is aware of the plea and has expressed no objections.

Assistant U.S. Attorney Jarrod Leaman said the amount of time remaining on McGirt’s sentence would be determined by the federal Bureau of Prisons as part of the presentence report.

McGirt was first convicted in state court in 1997 and sentenced to life without parole and two 500-year prison sentences for rape, lewd molestation and sodomy of a 4-year-old girl in 1996.

The conviction and sentence were overturned in 2020 by the U.S. Supreme Court, which found that much of eastern Oklahoma, including a large swath of its second-largest city, Tulsa, remains a Native American reservation because it were never disestablished by Congress. The Oklahoma Court of Criminal Appeals has since expanded that ruling to include other tribal reservations in that part of the state.

McGirt was later convicted in federal court of sexual abuse of a child and sentenced to life in prison. But an appeals court overturned that conviction this year, finding that the jury instructions regarding inconsistent statements by key witnesses against McGirt were incorrect.