The US Supreme Court ruled on Monday 1st April that a convicted murderer on death row in Missouri has no right to a "painless death".
The ruling clears the way for the execution of Russell Bucklew, who asked for gas rather than lethal injection, citing an unusual medical condition.
Bucklew, 50, argued the state's preferred method amounts to legally banned "cruel and unusual punishment".
Bucklew was sentenced to death in 1996 for rape, murder and kidnapping in an attack against his ex-girlfriend and her new partner and six-year-old son.
In recent court filings, Bucklew argued that his congenital condition, cavernous hemangioma, might cause him excessive pain if he is put to death by lethal injection.
The condition causes blood-filled tumours in his throat, neck and face, which he said could rupture during his execution causing him extreme pain and suffocation.