Alabama prepares to carry out first execution using nitrogen gas asphyxiation

Convicted murderer Kenneth Smith has previously survived one execution attempt by lethal injection in 2022

Alabama on Thursday evening plans to carry out the first known judicial execution of a prisoner using asphyxiation with nitrogen gas, a closely watched new method the state hopes to advance as a simpler alternative to lethal injections.

Kenneth Smith, convicted of a 1988 murder-for-hire, is a rare prisoner who has already survived one execution attempt. In November 2022, Alabama officials aborted his execution by lethal injection after struggling for hours to insert an intravenous line’s needle in his body.

Under the new protocol, which was announced in a heavily redacted form in September, officials will restrain Smith in a gurney and strap a commercial industrial-safety respirator mask to his face. A canister of pure nitrogen will be attached to the mask in a process intended to deprive him of inhaling oxygen.

Alabama has called it the “the most painless and humane method of execution known to man”, and says he should lose consciousness within a minute or two, and die soon after.


Opponents of capital punishment, including United Nations human-rights experts, have said the method amounts to experimenting on humans and could merely injure him without killing him, or lead to a torturous death.

On Thursday, Smith asked the US supreme court to halt the execution so that justices can consider an appeal, challenging a decision by the 11th Circuit US court of appeals (COA). The high court’s conservative majority has generally voted in recent years against delaying scheduled executions.

The COA on Wednesday denied Smith’s request to halt the execution to allow his legal challenges to the new protocol to proceed.

The appeals court decision came after the supreme court earlier denied Smith’s application to halt the execution on the grounds that a second attempt to execute him by any means – after a botched first try – amounts to unconstitutional “cruel and unusual punishment”.

Smith's lawyers fear that the mask would not properly seal against Smith's face, allowing oxygen to seep in, delaying or even averting the moment of unconsciousness but risking serious brain injury. They have proposed Alabama instead uses a hood pre-filled with pure nitrogen, to be plunged over his head, or else to use a firing squad.

Death penalty experts also say the state has not provided enough information about how it would mitigate any danger faced by execution officials and others inside the death chamber when the invisible, odourless gas is released.

Rev Jeff Hood, spiritual adviser to Smith, who will be at Smith’s side, had to sign a form acknowledging the risk that the execution method poses to others.

As the waiver notes, nitrogen makes up about 78 per cent of normal breathing air, so if the concentration of nitrogen is increased, displacing oxygen, there is a risk of unconsciousness and even death.

US states that use capital punishment have found it increasingly difficult to get drugs for lethal injections, partly because pharmaceutical companies forbid supplying them to prisons to comply with a European trade ban on goods to be used in torture or executions.

Besides Alabama, lawmakers in Oklahoma and Mississippi have approved similar nitrogen-asphyxiation execution protocols in recent years, but have yet to put them into practice.

Maya Foa, joint executive director of the international human rights legal non-profit group Reprieve, said the new method is “the latest effort to obscure the violence of the state taking a human life”.

“The state of Alabama has tortured Mr. Smith once, stabbing him with needles for hours, and by using him as a guinea pig for a dangerous, untested new method of execution, it is torturing him again,” Ms Foa said in a statement.

Smith was convicted of murdering Elizabeth Sennett, a preacher's wife, after he and an accomplice accepted a $1,000 fee from her husband to kill her, according to trial testimony.

Eleven of 12 jurors voted to sentence Smith to life in prison, but an Alabama judge overruled their recommendation under a law that has since been abolished as unconstitutional.

Some of Sennett’s relatives have said they support the execution, scheduled for 6pm local time at Alabama’s Holman Correctional Facility, and that they planned to attend.

“Why should we have to suffer?” her son Charles Sennett told the WAAY-13 news channel this month.

“And some of these people out there say, ‘Well, he doesn’t need to suffer like that.’ Well, he didn’t ask Mama how to suffer? They just did it. They stabbed her multiple times.” – Reuters