U.S. Supreme Court Justice Samuel Alito issued an order late Tuesday halting the execution of Missouri inmate Russell Bucklew about an hour before he was set to die by lethal injection.

The action most likely means the full Supreme Court will review the order Wednesday and decide whether or not to hear the merits of Bucklew’s challenge to his execution.

Bucklew, 46, reportedly suffers from a congenital condition that has weakened and malformed his blood vessels. He has tumors growing in his nose and throat, he bleeds from his eyes and ears and he has constant pain in his face that requires pain medicine every few hours. He told the Associated Press that, because of his condition, he was scared of what might happen.

Attorneys for Bucklew, a convicted killer, had asked the courts for a stay of execution owing to his medical condition, which they said would make it more likely he would suffer a prolonged, painful death during the execution.

Alito, who handles emergency matters for Missouri and other states covered by the 8th U.S. Circuit Court of Appeals, didn’t explain why he issued the order suspending Bucklew’s execution. But Missouri Attorney General Chris Koster issued a statement saying his office understands the full Supreme Court would consider Bucklew’s requests Wednesday.

With capital punishment dominating headlines, PostTV looks at the latest statistics on the death penalty in the United States, and in the 21 other countries that executed inmates in 2013. (Davin Coburn/The Washington Post)

A three-judge panel of the 8th Circuit court suspended the execution Tuesday after Bucklew’s attorneys asked the courts for the stay. The full 8th Circuit then reversed the panel’s decision later that evening, saying the execution could go ahead.

If it does, it would be the first in the United States since the botched Oklahoma execution last month that left death row inmate  Clayton Lockett writhing on a gurney.

“I’m sick about it not working on me. I’m afraid that it’s going to turn me into a vegetable, that I’d be brain dead,” Bucklew told the Guardian earlier this month. “You saw what happened down in Oklahoma. I’m the next guy up – am I gonna get all screwed up here? Are they gonna screw it up?”

Bucklew was scheduled to die for shooting and killing a man in 1996 before going on to beat, rape and abduct an ex-girlfriend.

Missouri moved from a three-drug protocol to the single drug pentobarbital late last year. However, none of the six inmates executed since the state made the change has shown any outward signs of pain or suffering, according to the AP. Still, when Lockett’s execution went awry, it prompted renewed concern and reignited the death penalty debate.

The AP and four other news organizations filed a lawsuit last week against the Missouri Department of Corrections, claiming the state’s refusal to provide information on the execution drug violates the public’s constitutional right to have access to information about the punishment. 

Also last week, Bucklew’s attorneys filed a motion asking the court to allow the videotaping of his death to record any constitutional violations — namely, cruel and unusual punishment — for future litigation.

Missouri has executed four people so far this year, which is as many executions as the state carried out between 2006 and 2013.