Alabama is set to carry out the first American execution using nitrogen gas on Thursday evening, potentially opening a new frontier in how states execute death row prisoners despite concerns from death penalty opponents about the untested method.
Several courts, including the U.S. Supreme Court, have allowed the execution to move forward, though lawyers for the condemned prisoner, Kenneth Smith, have made one more last-minute request for the nation’s top court to intervene.
As it stands, prison officials plan to begin the execution around 6 p.m. Central time. Mr. Smith, 58, is one of three men convicted in the 1988 murder of a woman whose husband, a pastor, had recruited them to kill her.
The protocol released by prison officials calls for strapping Mr. Smith to a gurney in the state’s execution chamber in Atmore, Ala., after which a mask will be placed on his head and a flow of nitrogen will be released into it, depriving him of oxygen. Mr. Smith’s lawyers say it would be the first nitrogen execution in the world. It would be the second time Alabama has tried to kill Mr. Smith, after a failed lethal injection in November 2022 in which executioners could not find a suitable vein before his death warrant expired.