GREENWOOD, Ark. (AP) — Ricky Dority spends most of his days playing with his grandchildren, feeding chickens and working in the yard where he lives with his son’s family.

It’s a jarring change from where he was just several months ago, locked in a cell serving a life prison sentence at Oklahoma’s Joseph Harp Correctional Center in a killing he said he didn’t commit. After more than two decades behind bars, Dority had no chance of being released — until he used his pandemic relief funds to hire a dogged private investigator.

The investigator and students at the Oklahoma Innocence Project at Oklahoma City University, which is dedicated to exonerating wrongful convictions in the state, found inconsistencies in the state’s account of a 1997 cold-case killing, and Dority’s conviction was vacated in June by a Sequoyah County judge.

Now, the 65-year-old says he’s enjoying the 5-acre property in a quiet neighborhood of well-to-do homes in the rolling, forested hills of the Arkansas River Valley outside of Fort Smith. “If you’re gone for a lot of years, you don’t take it for granted anymore.”

Dority is one of nearly 3,400 people who have been exonerated across the country since 1989, mostly over murder convictions, according to the National Registry of Exonerations. In Oklahoma, there have been more than 43 exonerations in that time, not including three new exonerations this year.

The cases underscore a serious problem facing a judicial system in which many old convictions resulted from overworked defense attorneys, shoddy forensic work, overzealous prosecutors and outdated investigative techniques.

The problem is particularly acute given Oklahoma’s history of sending people to death row, where 11 inmates have been exonerated since 1981. The issue has pushed a Republican-led legislative panel to consider whether a death penalty moratorium should be imposed.

In Oklahoma County, Glynn Ray Simmons was freed after spending nearly 50 years in prison, including time on death row, in a 1974 killing after a judge determined prosecutors failed to turn over evidence in the case, including a police report that showed an eyewitness might have identified other suspects.

And just this week, Perry Lott, who served more than 30 years in prison, had his rape and burglary conviction vacated in Pontotoc County after new DNA testing excluded him as the perpetrator. Pontotoc County, in particular, has come under intense scrutiny for a series of wrongful convictions in the 1980s that have been the subject of numerous books, including John Grisham’s “The Innocent Man,” which he produced into a six-part documentary on Netflix.

The most common causes of wrongful convictions are eyewitness misidentification, misapplication of forensic science, false confessions, coerced pleas and official misconduct, generally by police or prosecutors, according to the Innocence Project, a national organization based in New York.

In Dority’s case, he said he was railroaded by an overzealous sheriff and a state prosecutor eager to solve the killing of 28-year-old Mitchell Nixon, who was found beaten to death in 1997.

Investigators who reopened the case in 2014 coerced a confession from another man, Rex Robbins, according to Andrea Miller, the legal director of the Oklahoma Innocence Project. Robbins, who would plead guilty to manslaughter in Nixon’s killing, implicated Dority, who at the time was in a federal prison on a firearms conviction. Dority said he knew he didn’t have anything to do with the crime and found paperwork that proved he had been arrested on the day of the killing.

“I thought I was clear because I knew I didn’t have anything do with that murder,” Dority said. “But they tried me for it and found me guilty of it.”

Jurors heard about Robbins’ confession and testimony from a police informant who said Dority had changed bloody clothes at his house the night of the killing. They convicted him of first-degree murder and recommended a sentence of life without parole.

After years in prison, while most inmates spent their federal COVID-19 relief check in the commissary, Dority used his to hire a private investigator, he said. Bobby Staton had mostly investigated insurance fraud, but he took on the case and realized quickly that it was riddled with holes, Staton said.

He eventually turned to the university’s Oklahoma Innocence Project, which assigned a law student, Abby Brawner, to help investigate.

Their investigation turned when Staton and Brawner visited Robbins in the maximum-security Oklahoma State Reformatory in Granite, and he recanted his statement implicating Dority.

“It was pretty intimidating,” Brawner said. “Especially when you’re going in to meet someone who doesn’t know you’re coming and doesn’t want to talk to you.”

Brawner and Staton also learned the informant didn’t live at the home where he told investigators Staton showed up in bloody clothes. When the actual homeowner testified at a hearing this summer, the judge dismissed the case.

Dority’s original attorneys were ineffective for not discovering the informant didn’t live at the home, the judge said, giving prosecutors 90 days to decide whether they will retry him. That three months has been extended, and prosecutors have said they intend to ask the judge for more time for DNA testing. Dority, confident in his innocence, said he’s not concerned about additional forensic testing.

Sequoyah County District Attorney Jack Thorp and former Sheriff Ron Lockhart did not respond to requests for comment from The Associated Press. But Assistant District Attorney James Dunn, who is overseeing the case and was not in the office when it was originally prosecuted, said he agreed with the judge’s dismissal after hearing the homeowner’s testimony and learning a witness “was not credible.”

“The last thing I want to see is an innocent person in prison for a crime they didn’t commit,” Dunn said. “Because that means the person who actually did commit the crime, or those persons, are still out there.”

Meanwhile, Dority is learning to use a smartphone and the television remote control, he said. He’s thankful to Staton and the Innocence Project and says his case proves others are wrongfully imprisoned in Oklahoma.

“After they’ve done what they’ve done to me, I know there are people in that prison who are innocent that need to be out and need help getting out,” he said. “If they hadn’t gotten me out, I’d have been in there for the rest of my life.”