A man on death row in Missouri, who has already had his life spared from execution once before, is again asking for another reprieve, claiming the lethal injection will cause a gruesome and painful death because blood-filled tumors in his head might burst.

Russell Bucklew is scheduled to be executed tonight, for the second time, after he was granted a last-minute stay of execution less than an hour bef0re he was due to die by lethal injection in May of 2014.

Want to know exactly how a lethal injection works? It actually involves three drugs and two injections. To learn what each one does and how long it takes a death row inmate to die, watch the video below:

The US Supreme Court stopped Bucklew’s previously scheduled execution because of concerns over violating his constitutional right to an execution without cruel or unusual punishment.

Bucklew suffers from a rare medical condition called cavernous hemangioma. This causes weakened and malformed blood vessels, vein problems, and blood-filled tumors to grow in his head, throat, and on his lip.

Bucklew’s attorney, Cheryl Pilate, is once again asking for an intervention from the Supreme Court. She claims Bucklew’s condition has gotten worse and that his tumors will likely rupture and bleed during the lethal injection.