The first execution in the US using nitrogen gas will be carried out in the state of Alabama after the Supreme Court decided Wednesday not to intervene.
Kenneth Smith, 58, is scheduled to be executed by nitrogen gas during a 30-hour window starting on Thursday, according to multiple media outlets.
The new death penalty procedure is called nitrogen hypoxia, in which the person breathes in only nitrogen and dies from a lack of oxygen.
Smith's attorneys argued that the method violates the constitutional ban on cruel and unusual punishment, but the high court disagreed, making way for this landmark execution.
Smith was scheduled to die by lethal injection 14 months ago, but officials were not able to set an intravenous line before the execution warrant expired. His attorneys' attempts to stay the current execution were vanquished by Wednesday's Supreme Court decision.
Smith's execution would mark only the second time in US history that a state would attempt to execute an inmate after initially failing on the first attempt, according to officials.
Smith was sentenced to death for his role in the 1988 murder-for-hire plot of Elizabeth Sennett, 45, who was stabbed and beaten to death. Sennett's pastor husband, Charles, hired Smith and two others for $1,000 each to kill his wife and make it look like a burglary, according to court records.
Charles Sennett killed himself a week after his wife's murder once authorities shifted the focus of the investigation on him. Smith was eventually arrested for his part in the murder scheme.
Execution by nitrogen hypoxia has been approved by only three states: Alabama, Oklahoma and Mississippi. Alabama is the only state that has outlined a protocol for using it, indicating that Smith will be delivered the nitrogen gas through a mask.
Contrary to Smith's attorneys' claims that this method of execution is inhumane, Alabama state officials said that nitrogen hypoxia is "perhaps the most humane method of execution ever devised."
"Such treatment is much better than Smith gave Elizabeth Sennett nearly thirty-six years ago," they said.
