Alabama murderer Kenneth Smith held his breath in vain as officials executed him with nitrogen gas last night.
He was the first prisoner to be executed using this new method of capital punishment since lethal injections began in the US four decades ago.
According to witnesses allowed to watch the execution at Holman Prison in Atmore, he was restrained him in a gurney and a commercial respirator mask was strapped to his face.
A canister of pure nitrogen was attached to the mask that, once flowing, deprived him of oxygen.
Smith shook his head and writhed for about two minutes. He breathed deeply for several minutes before his breathing slowed and became imperceptible, and he was pronounced dead.
"It appeared that Smith was holding his breath as long as he could," Alabama Corrections Commissioner John Hamm told a press conference. "He struggled against the restraints a little bit but it's an involuntary movement and some agonal breathing. So that was all expected."
Smith, convicted of a 1988 murder-for-hire, had survived one execution attempt in 2022 when officials aborted his execution by lethal injection after struggling for hours to insert the needle into his body.
Officials said the gas is "the most painless and humane method of execution known to man," and predicted Smith would lose consciousness in less than a minute and die soon after.
Alabama has touted asphyxiation as a simpler alternative for prison systems that struggle to find veins or the required drugs for lethal injections.
Human rights lawyer Clive Stafford Smith, who has represented more than 400 people on death row in the US, told TalkTV what it is like for the state to execute his clients.
Kenneth Smith was the first prisoner to be executed using this new method of capital punishment. Credit AP
Elizabeth Sennett was murdered by Kenneth Smith in 1988.
“I have to be there for may clients and the executions always take place the middle of the night. I always come out of the execution chamber and look up at the stars and think 'My goodness, does that really make the world a safe place?'"
Smith mounted legal challenges in federal courts arguing that Alabama's new method amounted to unconstitutional "cruel and unusual punishment," but he failed to cross the high bar needed to have a judge order a delay of his execution.
Though poisonous gases such as hydrogen cyanide have been used in executions in the US in the past, this was the first time a death sentence was carried out anywhere using an inert gas to suffocate someone, capital punishment experts say.
"On March 18, 1988, 45-year-old Elizabeth Sennett's life was brutally taken from her by Kenneth Eugene Smith," Alabama Governor Kay Ivey, a Republican, said in a statement. "After more than 30 years and attempt after attempt to game the system, Mr Smith has answered for his horrendous crimes."
Smith was convicted of murdering Sennett, a preacher's wife, after he and accomplices each accepted a $1,000 fee from her husband to kill her, according to trial testimony.
"Nothing that happened here today is going to bring mom back," Mike Sennett said. "It's a bittersweet day, we're not going to be jumping around, hooping and hollering, hooraying and all that, that's not us. We're glad this day is over."
