(Web Desk) - The Supreme Court has rejected Kenneth Eugene Smith's Hail Mary request for a stay in execution, meaning he is set to become the first person in history to be put to death with nitrogen gas.
Smith was scheduled be executed at 6pm tonight at the William C. Holman Correctional Facility in Atmore, Alabama, although his death warrant extends to 6am.
The Supreme Court voted 6-3 to allow the execution to proceed, with the three Democrat-appointed Justices, Sonia Sotomayor, Ketanji Brown Jackson, and Elana Kagan dissented the opinion of their conservative colleagues.
Smith had begged for it to be called off, citing his fears that the experimental gassing method will cause excruciating pain or cause him to vomit.
Alabama Attorney General Steve Marshall insisted that the controversial method would be 'painless' for Smith.
As Smith now heads for the execution chamber, his prison pastor John Ewell told DailyMail.com that he is 'really struggling' to come to terms with his fate.
The Supreme Court yesterday denied an application for a stay. He filed another request today as the execution approached, however justices denied his desperate appeal and sent him to the chamber.
One of the primary reasons Alabama has turned to nitrogen gas for Smith's execution has been the widespread struggles American prisons have had in obtaining lethal injection drugs in recent years.
Despite warnings from human rights groups over the use of the method, AG Marshall insisted that Smith's fears are unfounded, a decision ultimately agreed by SCOTUS.
In her dissent, Justice Sotomayor wrote that she felt the execution method was cruel, as Smith will wear a mask that has never been fitted for his face until the moment he is strapped down, and officials won't intervene even if he begins choking on his own vomit.
Smith will also have the chance to say his last words, but he will be forced to speak them through the gas mask before the nitrogen is turned on.
Sotomayor felt Smith was a 'surprising candidate' for the untested method - with his previous scheduled execution in November 2022 called off after painful hours of botched attempts to inject him with an IV line.
She said he has been suffering from PTSD since being released from the execution table, 'reliving those hours strapped to the gurney.'
'Having failed to kill Smith on its first attempt, Alabama has selected him as its 'guinea pig' to test a method of execution never attempted before,' Sotomayor wrote.
Aged 22, Smith was one of two men convicted in the murder-for-hire slaying of Elizabeth Sennett, 45, the wife of preacher Charles Sennet Sr. who paid the men to kill his wife in an insurance plot.
His initial 1989 conviction was overturned on appeal, but he was retried and convicted again in 1996.