Richard Glossip, the former Oklahoma death row inmate who spent nearly three decades incarcerated over the 1997 killing of motel owner Barry Van Treese, pleaded guilty Thursday to a lesser accessory charge, and the murder charge was dismissed, his attorney Don Knight said.

Glossip had been sentenced to death in what prosecutors alleged was a murder-for-hire scheme, and he had been on the brink of execution three times before the U.S. Supreme Court threw out his conviction and he was released on bond in May to await retrial.

The plea, reported by KCRA and LiveNOW from FOX, caps one of the longest-running death penalty fights in the country.

The development is a genuine reversal for a case that became a national cause: Glossip's longstanding claims of innocence drew support from Kim Kardashian, and the case attracted international attention after Oscar winner Susan Sarandon took up his cause in real life.

The 2017 documentary film "Killing Richard Glossip" further amplified the case. Courts in Oklahoma had set nine different execution dates, and Glossip came so close to death that he ate three separate last meals — yet no execution was ever carried out.

Attorney Don Knight said Glossip "has more than paid his debt to society" for a crime he maintains he did not commit.

Van Treese was beaten with a baseball bat in Oklahoma City, and another man, Justin Sneed, admitted robbing and killing him but testified that he did so after Glossip promised to pay him $10,000. Sneed was the state's key witness against Glossip and was sentenced to life in prison.

By pleading guilty to being an accessory, Knight said, Glossip acknowledged the prosecution's allegations that he helped place plexiglass over a broken window at the motel, where Van Treese's body was inside the room — though Knight said Glossip did not know it was there and never saw it.

The prosecution also said Glossip did not immediately tell police that Sneed had told him he killed Van Treese; Knight said Glossip did not believe that was true at the time.

The strangest turn in the case came in 2015, when Glossip was held in a cell next to Oklahoma's execution chamber, waiting to be strapped to a gurney and die by lethal injection — but the scheduled time came and went.

Behind the walls of the Oklahoma State Penitentiary, prison officials were scrambling after learning one of the lethal drugs they received didn't match the execution protocols.

That drug mix-up ultimately led to a nearly seven-year moratorium on executions in Oklahoma, according to the AP report carried by the Bluefield Daily Telegraph, a consequence that reshaped capital punishment in the state well beyond Glossip's own case.

Oklahoma Attorney General Gentner Drummond, who had previously said the state would seek to retry Glossip on a murder charge but would not pursue the death penalty again, called accepting the plea "a difficult decision for me and, more importantly, the Van Treese family."

In a statement to media outlets reported by the Bluefield Daily Telegraph, Drummond said both sides recognized that this path ensures a conviction related to Van Treese's killing and gives the state the best chance to secure additional prison time for Glossip.

The Van Treese family had asked the U.S. Supreme Court to leave Glossip's conviction and sentence intact before the high court overturned it.

Glossip will be sentenced in December, when he could be released or sent back to prison for another 15 years, his attorney said, while Drummond indicated prosecutors will ask for more prison time.

"I'm grateful for all my attorneys and all their hard work, and I'm grateful to you standing by my side," Glossip said after the plea. Knight maintained that Glossip "had nothing to do with the murder, none of the planning, or carrying it out."

The December sentencing will determine whether a man who served three last meals walks free — or returns to custody for the accessory role he has now acknowledged.