Yet just a couple of hours before Glossip was to be strapped to the gurney, the Oklahoma Court of Criminal Appeals suddenly blocked his execution, issuing a temporary stay in order to give “fair consideration” to new evidence presented by Glossip’s lawyers. Later, when he was finally able to check his phone, Knight had 150 emails to read. It was not until the following night that he was able to call Tapley to find out what he knew.

In fact, it was too late. By the time Knight’s paralegal came into their office the next morning and listened to the message, the preliminary execution protocols were underway. Knight was hundreds of miles from his desk, at the prison in McAlester, Oklahoma, in an area that did not allow cellphones.

“This is Joe. I was in a cell with Justin Sneed in 1997 in Oklahoma County Jail for five or six months. He told me all about his case. I think I might be able to help you.”

As he watched the news segment, Tapley felt certain that Sneed had framed Glossip. His story did not match what he remembered Sneed saying about the crime in 1997. Tapley wasn’t alone. In August, after Glossip’s case was featured on Dr. Phil, a man named Michael Scott came forward to say that he had spent time in prison with Sneed, who talked openly about his crime. “Among all the inmates, it was common knowledge that Justin Sneed lied and sold Richard Glossip up the river,” Scott said. Yet the execution was to proceed as scheduled, on September 16.

Tapley knew the name. More than that, he knew the man responsible for sending Glossip to his death: Tapley’s onetime cellmate Justin Sneed. The two had met at the Oklahoma County Jail in 1997. At the time, neither had reached his 20th birthday. Sneed had been arrested after using a baseball bat to kill a man named Barry Van Treese, the owner of the Best Budget Inn, a seedy motel in Oklahoma City, where he worked as a maintenance man. Sneed would later escape the death penalty after implicating Glossip, his supervisor, testifying that Glossip offered him several thousand dollars to kill on his behalf. Glossip says this was a lie. While he admitted that Sneed had told him he killed Van Treese on the morning of January 7, 1997 — and that he initially withheld what he knew from police — Glossip insisted that he had nothing to do with the murder.

But then he saw the report on the 6 o’clock news: The state of Oklahoma was ready to kill Richard Glossip. Gov. Mary Fallin had rejected his plea for a 60-day stay. His execution was scheduled for 3 p.m. the next day.

J OSEPH TAPLEY DIDN’T WANT his name in the press. He had worked too hard, since leaving prison in 2002, to get his life on track. Today he owns a business and has a wife and kids. The last thing he wanted when he sat down to watch TV on the evening of September 15 was to get dragged into anything that might bring him or his family any harm.

This past Sunday, Knight sat down with Tapley in his kitchen. Tapley told him what he remembered from his months with Sneed. In an affidavit signed the next day, Tapley said that Sneed had offered him “very detailed accounts” about his crime, including how hard it had been to kill Van Treese. “I am sure that Justin Sneed acted alone,” Tapley said. “He never gave me any indication that someone else was involved. He never mentioned the name of Richard Glossip to me.” If Sneed had, Tapley said, he would “definitely” remember it.

Tapley also said that at the time, Sneed “was very concerned about getting the death penalty. He was very scared of it. The only thing that mattered to him was signing for a life sentence.”

To prove that he was telling the truth about his access to Sneed, Tapley provided the number of their shared cell and drew a picture of the jail’s layout. He also showed Knight a Bible he had with him in jail that appeared to bear Sneed’s signature. Photos of both are attached to the affidavit, which was filed with the Court of Criminal Appeals on Monday, September 21.

T APLEY’S AFFIDAVIT is just the latest in a growing collection of evidence compiled by Glossip’s attorneys as their client faces his next execution date of September 30. The documents contain some contradictions — in August, Sneed’s mother told a defense investigator that her son had sent her a letter from the Oklahoma County Jail, where he was housed with Tapley, saying that others besides himself had been involved in the murder — “powerful and important people,” in her recollection. But even such inconsistencies point away from the state’s version of events, in which Sneed acted under Glossip’s sole control. And the latest affidavit from Tapley is consistent with the earlier affidavit of a former drug dealer who used to do business at the Best Budget Inn — and who said that, contrary to his claims in court, Sneed was in the grip of a severe meth addiction and would often steal in order to sustain it. “Justin Sneed had the twitches of a person who uses methamphetamine,” Tapley said. “He was ‘tweaking’ while he was in jail.”

Also among the most recent affidavits is the analysis of forensics experts who say that the trial testimony of the medical examiner, Dr. Chai Choi, was fatally flawed. At trial, Dr. Choi testified that Van Treese slowly bled to death over as many as eight hours. But upon examining the original autopsy report, investigative reporter Phil Cross of Oklahoma City station Fox 25 discovered “significant discrepancies” between the document and Dr. Choi’s testimony. There was “no mention of blood loss“ in the autopsy report, Cross reported earlier this month. This was significant: Multiple jurors told Cross that their decision in Glossip’s case was partly motivated by the fact that Glossip might have been able to save Van Treese’s life if he had gone to police as soon as he caught wind of Sneed’s actions. But according to an affidavit from forensic pathologist Michael M. Baden, it would have been too late: Van Treese was dead “within minutes” of being struck on the head with the baseball bat. “More rapid medical attention would not have changed the outcome.”

With his client’s new execution date one week away, Knight believes there is a “treasure trove” of people like Tapley and Scott who could prove Glossip’s innocence. But finding them — and convincing them to come forward — has been difficult. This is not particularly surprising: For those who have left prison, it would mean thrusting one’s criminal past into the public eye, as Michael Scott learned last weekend, when The Oklahoman ran a news story questioning his credibility. The article, which was based on a 2005 Department of Corrections document, included Scott’s old mug shot and detailed his limited education, the many illegal drugs he had used at 18, and the fact that he admitted to having lied many times in the past.

To Knight, the leaking of the 10-year-old record in Scott’s case was retaliatory — a clear attempt at intimidating anyone else who might come forward. “If that’s what the state can do to people who are out,” he told The Intercept, “imagine what they can do to people who are in.” Indeed, according to Knight and his colleagues, a number of people currently imprisoned with Sneed at Joseph Harp Correctional Facility have declined to speak, not because they deny knowing anything, but out of concern that they would lose their placement at the medium security prison and be sent somewhere worse.

For his part, Tapley makes it clear in his affidavit that he never wanted to come forward. He had hoped someone else might act first. “I had been thinking of calling with this information for a month or so before the execution,” he said, “but I always thought someone would stop it.” But ultimately, it was his wife — and his conscience — that moved him to act. “If Mr. Glossip had been killed and I had not done anything, I would have felt terrible for the rest of my life,” he said.

There are good reasons to take any kind of jailhouse testimony with a grain of salt. But there is also an irony in questioning the credibility of people like Tapley or Scott while defending Glossip’s conviction, as the editorial boards of both The Oklahoman and the Tulsa World have done. After all, if we have to dismiss the claims of former felons with very little to gain — and much to lose — by speaking out on Glossip’s behalf, how can anyone defend a death sentence based solely on the word of an admitted killer with the ultimate incentive to lie?

Whether Tapley’s decision to break his silence will make a difference remains an open question. But one thing is certain: Had the execution gone forward last week, “it would have been too late,” said Knight. Glossip would be dead by now. “And this information would never have come out at all.”

Additional reporting: Jordan Smith

Top photo: 2007 Google Maps image of the Budget Inn on Council Road in Oklahoma City, where Barry Van Treese was murdered.