The Supreme Court on Monday said it will hear an appeal from Oklahoma death row inmate Richard Glossip, who has steadfastly maintained his innocence and averted multiple attempts by the state to execute him.

Glossip was sentenced in a 1997 murder-for-hire of the owner of the motel where he worked.

The case won’t be argued until the fall. Glossip now has the support of the state’s Republican attorney general, Gentner Drummond, who says Glossip’s life should be spared because he did not get a fair trial.

“Public confidence in the death penalty requires the highest standard of reliability, so it is appropriate that the U.S. Supreme Court will review this case,” Drummond said in a statement Monday. “As Oklahoma’s chief law officer, I will continue fighting to ensure justice is done in this case and every other.”

John Mills, an attorney for Glossip, said his client is innocent. “He has no criminal history, no history of misconduct during his entire time in prison, and has maintained his innocence throughout a quarter century wrongfully on death row. It is time – past time – for his nightmare to be over,” Mills said in a statement.

The Supreme Court blocked the latest effort to execute Glossip in early May.

Despite Drummond’s doubts about the trial, an Oklahoma appeals court upheld Glossip’s conviction, and the state’s pardon and parole board deadlocked in a vote to grant him clemency.

But Drummond also has said he does not believe Glossip is innocent of the murder-for-hire killing of his former boss, Barry Van Treese, in 1997. Another man, Justin Sneed, admitted robbing and killing Van Treese after Glossip promised to pay him $10,000. Sneed received a life sentence in exchange for his testimony and was the key witness against Glossip.

Two separate independent investigations have revealed problems with the prosecution’s case.

Drummond said that Sneed lied on the witness stand about his psychiatric condition and his reason for taking the mood-stabilizing drug lithium and that prosecutors knew Sneed was lying.

Also, evidence was destroyed, Drummond said.

Some Republican state lawmakers who support the death penalty have joined the growing chorus of Glossip supporters who are seeking to overturn his conviction.

Glossip’s case has been to the Supreme Court before. He was given a reprieve in 2015, although the court later ruled 5-4 against him in a case involving the drugs used in lethal executions.

Glossip has been just hours away from being executed three times. His last scheduled execution, in September 2015, was halted just moments before he was to be led to the death chamber when prison officials realized they had received the wrong lethal drug. That mix-up helped prompt a nearly seven-year moratorium on the death penalty in Oklahoma.