An appeals court in Oklahoma halted the execution of Richard Glossip, 52, just two hours before his scheduled death on Wednesday. Glossip has spent 18 years on death row, and he has consistently maintained his innocence in the 1997 murder of Barry Van Treese, who was found beaten to death at a motel in Oklahoma City.

On Monday, just two days before Glossip was scheduled to be executed by lethal injection, his defense attorney Don Knight held a press conference outside the Oklahoma state capitol building and called on Governor Mary Fallin to issue a 60-day stay. Glossip's legal team released "dozens" of pages of documents that cast further doubt on his controversial conviction. The court issued the stay to give Glossip's attorneys a chance to review the new evidence.

In January 1997, Van Treese, the owner of a run-down motel in Oklahoma City, was found dead in room 102 of his own establishment. Investigators concluded that someone had beaten him to death with a baseball bat.

The police found fingerprints belonging to Justin Sneed, the motel's maintenance man, all over room 102. Sneed later confessed to the crime. Prosecutor's alleged that Glossip, the manager of the Best Budget Inn, masterminded the murder. Sneed testified against Glossip in court to avoid the death sentence. In 1998, a jury found Glossip guilty and sentenced him to death.

Oklahoma City District Attorney David Prater described Monday's press conference as a "bullshit PR campaign." "All they are trying to do is abolish the death penalty in the state of Oklahoma and this country by spreading a bunch of garbage," Prater told a local Fox 25 TV station.

Among the documents released on Monday was a letter from O'Ryan Justine Sneed, Justin Sneed's daughter. "I strongly believe he [Glossip] is an innocent man [who] is sitting on death row," she wrote last October. "For a couple of years now, my father has been talking to me about recanting his original testimony, but he has been afraid to act upon it, in fear of being charged with the death penalty."

There was also an affidavit from a man called Richard Allan Barrett that challenges the dynamic between Glossip and Sneed presented to the jury by prosecutors. "I saw nothing to make me think that Justin Sneed was controlled by Richard Glossip," Barrett stated. Barrett said he frequently dealt meth with Glossip's brother Bobby at the motel. According to the same affidavit, Sneed would shoot up meth "6 to 7 times a day," and he was addicted to the drug "in a bad way."

"As far as I know, Richard Glossip was a good-hearted guy who was not involved in Bobby Glossip's drug business" Barrett said.

Glossip was granted a retrial in 2004. James Clark, senior death penalty campaigner at Amnesty International, contends that Glossip's legal representation at both hearings was "inadequate" and failed to cross examine witnesses in the case. "One of the most significant ways that the death penalty is discriminatory is the lack of access to adequate legal representation," Clark said.

When a case comes down to a wire and execution is approaching, Clark said, "Inmates will often have the top quality attorney teams and civil rights organizations behind them, which in the early stages they didn't have access too."

"There's often this tendency on the part of the state to have supreme confidence in the judicial process," Clark said before the announcement that the execution would be halted. "Even though we know it can be so deeply flawed."

The US has executed 1,415 prisoners since 1976, and 155 people who faced the death penalty have been exonerated since the mid-70s. Ten of the people who were found to have been wrongfully convicted were from Oklahoma.

_Follow Tess Owen on Twitter: _@misstessowen

Top photo shows __Nancy Ogden, sister of convicted murderer Richard Glossip, comforting her grandson Kevin Ogden at a demonstration protesting the the scheduled execution in Oklahoma on September 15, 2015.