A ruling Thursday by the Alabama Supreme Court moved the state closer to executing an inmate in a way no state has ever done.

Alabama’s nitrogen hypoxia method, five years in the making, would use a gas mask to cause death. It is an alternative to the state’s standard method, lethal injection.

Nitrogen makes up 78% of the air people breathe. Almost all the rest, 21%, is oxygen. With nitrogen hypoxia, the inmate would breathe pure nitrogen and no oxygen until they die.

The lawmaker whose bill authorized the new method believes it will be a humane form of capital punishment.

Lawyers for the inmate the state plans to execute by nitrogen hypoxia — Kenneth Eugene Smith — told a federal court at one point that the method was a feasible alternative to lethal injection that was less likely to cause suffering. But they are now fighting Smith’s execution by nitrogen hypoxia, too, calling it experimental.

A main concern is that Alabama has revealed nothing about how the process will work except in a redacted court document.

“A new form execution which has never been used before, there are going to be a lot of problems with that because it really is experimentation,” said Deborah Denno, a professor at Fordham Law School who has researched and written about executions. “It’s literal experimentation. Nobody ever, as far as we know, has killed somebody this way, unless that was a murder that we weren’t familiar with. Even though some people say this is a very effective procedure, they wouldn’t know that because literally nobody has ever done it.”

Dr. Joel Zivot, an anesthesiologist and intensive care physician at Emory University Hospital who has studied lethal injection, said the lack of information about Alabama’s new method is glaring.

“Why Alabama thought about this, I guess, is because it is true that nitrogen gas when breathed, can kill you,” Zivot said. “We know this broadly in two places. We know that people have committed suicide by breathing nitrogen gas. And we know that there have been deaths by accidental nitrogen gas exposure in industry.

“It is true that nitrogen gas inhalation can kill people? Yes, that’s true. But whether or not it creates the kind of death that will be seen to be not cruel, there is no evidence that there’s any proof of that at all. (Alabama’s) decision is just to try it and to see what happens. They cannot point to any trial or any experiment or anything to say that they’ve got a method now that won’t be cruel.”

Smith was convicted of capital murder for the murder-for-hire of Elizabeth Dorlene Sennett in her home in Colbert County in 1988. Sennett was a pastor’s wife who was beaten and stabbed. Smith confessed to his role in the crime and was convicted in 1989 and again in a second trial in 1996.

Alabama tried to execute Smith by lethal injection in November 2022 but called off the procedure because the execution team could not connect to Smith’s veins. Smith claimed he was subjected to cruel and unusual punishment because he was strapped to a gurney for hours and poked with needles. The failed execution was the second in a row for Alabama and prompted Gov. Kay Ivey to temporarily suspend executions last year.

After the failed execution attempt, Smith asked federal courts to block the state from trying again to kill him by lethal injection. Smith’s lawyers said the state had an alternative method, nitrogen hypoxia.

Read more: Alabama Death Row inmate Kenneth Eugene Smith can die by nitrogen hypoxia, Supreme Court rules

“Mr. Smith is thus in a rare position of having proof that an execution by lethal injection caused him severe pain, despite a feasible and available alternative―nitrogen hypoxia―that would have entirely avoided the veinous access issue, and assuming proper administration, would cause an individual to lose consciousness within seconds, and experience no pain or discomfort while dying within minutes,” Smith’s lawyers wrote in his amended lawsuit, filed in December 2022. “That feasible and available alternative method of execution significantly reduces the intolerable risk of torture, cruelty, or substantial pain associated with Defendants’ lethal injection process.”

At that time, state officials had never confirmed the state was ready to use the nitrogen hypoxia method.

Nitrogen Hypoxia execution process?

That confirmation finally came in August, when Attorney General Steve Marshall asked the state Supreme Court to issue an order allowing the state to execute Smith by nitrogen hypoxia. Marshall included a redacted version of the nitrogen hypoxia protocol with his request to the court.

On Thursday, the Alabama Supreme Court, in a 6-2 ruling, granted Marshall’s request. The justices did not mention the execution method in the order. They did not issue opinions or dissents.

The non-redacted portion of the execution protocol describes some of the steps in the process, including the inspection of the equipment used and other preparations.

As with lethal injection, the inmate is placed on a gurney in the execution chamber. The execution team places a mask on the inmate’s face and adjusts it. A tube provides breathing air through the mask.

After other preliminary steps, curtains open to allow people in the witness rooms to see into the execution chamber. The warden reads the death warrant, and the inmate has up to two minutes to make a final statement.

After a check for any last-minute stays on the execution and a final inspection of the mask, the warden activates the nitrogen hypoxia system, presumably taking away the air and sending nitrogen through the tube to the mask instead. Redactions conceal parts of those steps.

The unredacted portion says that nitrogen gas is administered for 15 minutes or for five minutes after a flatline indication on an EKG (heart monitor), whichever is longer.

Denno said the redacted protocol leaves out information that the state should disclose.

“For a method that has never been used before they should be spelling out every stage,” Denno said. “In fact, the beginning of this protocol should be an overall description of the purpose for this method of execution, which they’ve never given. They’ve never said why they are using this method of execution. Why are they doing it? What’s the advantage? And they never say that.”

An example of information the state should disclose is how it determined the duration for administering the nitrogen, Denno said.

“They say they’re going to wait five minutes (after an EKG flatline), but why five minutes?” Denno said. “They should be explaining.”

The protocol includes inspections of devices with alarms to monitor oxygen levels in the execution chamber and witness rooms. But Denno and Zivot said the document still falls short of describing safety measures needed because of the dangers of nitrogen gas. They also note there is no explanation of how the mask will fit tightly enough to avoid leaking and whether the inmate is strapped down or otherwise prevented from taking off the mask or loosening it by movement.

Zivot said it’s not enough to simply say, “We’re going to give him a mask to breathe and he’ll breathe in it and he’ll die. It’s the details of exactly how this will happen which are critically important.”

Who came up with the idea?

Former state Sen. Trip Pittman of Baldwin County sponsored the bill that authorized nitrogen hypoxia. Pittman said he got the idea from Oklahoma, which authorized nitrogen hypoxia in 2015 but has never used it. Alabama lawmakers approved Pittman’s bill in 2018 at a time when lethal injection, the state’s main form of execution, faced uncertainty because of litigation and availability of the lethal drugs.

Pittman said he based his support of the idea partly on information about industrial accidents caused by nitrogen inhalation. He said the victims lose consciousness quickly, leading to the conclusion that they did not suffer painful deaths. He said it would be comparable to what happens when an airplane loses cabin pressure and the pilot and passengers pass out.

“If you’re knocked out, then you’re unconscious, and you’re not in pain,” Pittman said.

The former senator noted that tanks of nitrogen are readily available for industrial use. And he noted that some people have chosen to use nitrogen as a method of suicide, which he said supports the idea that it does not cause suffering.

“There’s two arguments,” Pittman said. “The first argument is the death penalty. If you’re for or against the death penalty. And that’s a separate argument. But if you have a death penalty, and Alabama has a death penalty. And then you’re going to carry out that term, I believe you ought to use the most humane method possible.”

In September, the Wall Street Journal published an opinion article by Stuart E. Creque, a technology marketing executive and screenwriter with the headline, “Finally, There’s a Humane Method of Execution.” Creque wrote that executions from breathing pure nitrogen would be painless because the first symptom would be a loss of consciousness. Creque based his conclusions on reports on industrial accidents from nitrogen asphyxiation.

After Oklahoma passed the bill authorizing nitrogen hypoxia in 2015, the New Yorker published an article saying that Creque is usually credited with the idea of nitrogen executions because Creque suggested it in the 1990s after a fatal accident involving NASA technicians exposed to the gas. In 2015, Oklahoma was looking for an alternative method after the lethal injection execution of Clayton Lockett, who died of a heart attack 43 minutes after his lethal injection started.

Zivot said there is no evidence that supports the assertion that a person being forced to breathe only nitrogen will not suffer. Zivot said there is some information from pilot training in low-oxygen situations and anecdotal information about industrial accidents when people were found dead in hypoxic environments.

“What you’re doing of course is you’re asphyxiating people,” Zivot said. “And that’s how they’re dying. It’s not like you give them a gas and the gas itself causes unconsciousness. Like an anesthetic gas. It’s just no oxygen. So you’re choking people to death. That’s what you’re doing.

“It’s not like you go to the doctor and you breathe, nitrous oxide, for example. Or laughing gas or something. That’s something different. There are a variety of gases we use in anesthesiology in the operating room that cause cause unconsciousness, unresponsiveness, when they’re mixed with oxygen. So we never would give patients no oxygen. We would give them oxygen and these other gases. And these other anesthetic gases that actually affect the body. Whereas nitrogen is not an anesthetic in any way. It just isn’t oxygen. That’s how it works.”

Zivot said he opposes the use of medicine or science in carrying out the death penalty. He studied autopsy reports of inmates executed by lethal injection and determined that most experienced pulmonary edema, which involves the lungs filling with fluid.

“Whereas lethal injection was represented as a kind of peaceful sort of death where maybe a prisoner would fall asleep and then die, in fact, what was really happening was that they were slowly drowning in their own bloody secretions,” Zivot said. “And that’s how they died. And to my mind, and I would say to the minds of most people, that sounds like a cruel way to go.”

Zivot helped arrange and observed a private autopsy of Joe Nathan James Jr. after Alabama executed James in July 2022. last year. It took several hours for Alabama to execute James because of difficulty connecting to his veins. Zivot said the autopsy showed evidence that the state used a “cutdown” procedure to try to access James’ veins, an incision to expose the vein.

Dr. Boris Datnow, a Birmingham-based private autopsy pathologist who performed the autopsy, said there was no evidence of a cutdown procedure. The Alabama Department of Forensic Sciences reported no evidence of a cutdown procedure in its autopsy report.

Denno said the last time a new method of execution was used was when Texas used lethal injection for the first time in 1982.

Alabama state Sen. Chris Elliott, a Republican from Baldwin County, said death row inmates have made a mockery out of the execution process by drawing out legal challenges by any way they can.

“That’s why we’ve run into problems with lethal injection, obtaining the drug, administration of the drug, etc.,” Elliott said. “People in Alabama believe in the death penalty and they believe in putting somebody to death. If the criminals that have been convicted and been sentenced to death don’t like what’s on the table now, then there’s another option for them.”

“If you don’t like what’s behind Door A, we’ve got another solution for you,” Elliott said.

Pittman, the former senator who sponsored the bill, said he believes it was the right step.

“I do believe in the death penalty,” Pittman said. “I think it is a deterrent to crime. And I do think if you’re going to have it the best do would be in the most humane way possible. So to that extent, I do continue to support the bill.”