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, are making 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. It would be the second time the state 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.
The nitrogen method is similar to that used in some assisted suicides in Europe and elsewhere. Lawyers for the state have argued that death by nitrogen hypoxia, as it is known, is painless, with unconsciousness occurring in a matter of seconds, followed by stoppage of the heart. They also note that Mr. Smith and his lawyers have themselves identified the method as preferable to the troubled practice of lethal injection in the state.
Mr. Smith’s lawyers contend that Alabama is not adequately prepared to carry out the execution, that a mask — rather than a bag or other enclosure — could allow in enough oxygen to prolong the process and cause Mr. Smith to suffer, and that Mr. Smith, who has lately experienced frequent nausea, could choke under the mask if he vomits.
A federal appeals court on Wednesday night voted 2-1 to allow the execution to go forward after the concerns expressed by Mr. Smith’s lawyers. One of the lawyers, Jeffrey H. Horowitz, said that the legal team would appeal that case to the Supreme Court, in what amounts to a potential last-ditch effort to spare his life.
The Supreme Court already declined to intervene in the lawyers’ appeal of a separate case on Wednesday, in which they had argued that trying to execute Mr. Smith a second time amounted to unconstitutional cruel and unusual punishment, in part because of how harrowing the failed 2022 execution attempt had been.
Mr. Smith’s case is unique in part because the jury that convicted him of murder also voted 11 to 1 to sentence him to life in prison, rather than death, but the judge overruled their decision. Alabama has since made it illegal for judges to overrule juries in imposing the death penalty — a prohibition that now exists in every state — but the new law did not apply to previous cases.
If the execution goes forward without visible problems, it is likely the procedure would also be examined by other states facing mounting problems obtaining lethal injection drugs from drug companies in the face of pressure from medical groups, activists and lawyers. Mississippi and Oklahoma have authorized their prisons to carry out executions by nitrogen hypoxia if they cannot use lethal injection, though they have never tried to do so.
Nitrogen makes up about 78 percent of the air on Earth and is normally harmless; oxygen, which makes up about 21 percent, is essential to human life. But when nitrogen is pumped into an enclosure, or a mask, it can quickly push out the oxygen and lead to rapid unconsciousness and death.
Alabama’s first attempt at the method comes after several botched or difficult executions in which executioners struggled to find veins on the men they were trying to put to death.
In 2022, executioners tried for hours to access the veins of Joe Nathan James, ultimately slicing into one of his arms in what is known as a “cutdown” in order to administer the fatal drugs, according to a private autopsy. Since 2018, three death row prisoners in the state, including Mr. Smith, have survived execution attempts because of difficulty inserting intravenous lines.
Four days after failing to execute Mr. Smith in 2022, the state’s governor, Kay Ivey, a Republican, halted all executions in the state and asked the prison system, the Alabama Department of Corrections, to review its procedures. The state resumed executing people in 2023, killing two men by lethal injection.
If the execution goes ahead Thursday evening, the plan is for Mr. Smith to be accompanied in the execution chamber by the Rev. Jeff Hood, a spiritual adviser who has spoken with him frequently over the last two months. Mr. Hood said early on Thursday that he had met with Mr. Smith the day before and that he had frequently been throwing up in a trash can at the prison.
Mr. Hood said that both he and Mr. Smith view the execution as increasingly likely to take place and are growing more afraid that there could be problems.
“We feel like we’re walking into some sick, twisted house of horrors,” said Mr. Hood, who met with prison officials on Wednesday in the execution chamber to discuss the protocols. “It feels like the more that this goes along, the less we know.”
“Kenny is terrified,” he added. “He’s terrified that this thing is going to completely torture him.”
Among the other witnesses to the execution will be Mr. Smith’s family members and lawyers, prison officials and five Alabama-based reporters. Some family members of the woman who was killed in the 1988 stabbing, Elizabeth Sennett, have also indicated that they plan to attend.
Ms. Sennett was stabbed 10 times in the attack by Mr. Smith and another man, according to court documents. Her husband, Charles Sennett Sr., had recruited a man to handle her killing, who in turn recruited Mr. Smith and a third man. Mr. Sennett arranged the murder in part to collect on an insurance policy that he had taken out on his wife, according to court records. He had promised the men $1,000 each for the killing.
Mr. Sennett later killed himself; one of the other men involved in the murder was executed by lethal injection in 2010, and the third was sentenced to life in prison and died in 2020.
Abbie VanSickle contributed reporting.