The execution table in the death-penalty chamber at the Oklahoma State Penitentiary in McAlester.

The colorless, odorless gas makes up 78 percent of our air.

Yet it is used in some assisted suicides in Europe. It is touted by some advocates for industry euthanasia of animals. And the gas – nitrogen – is what U.S. Air Force pilots are exposed to during high-altitude tests that gauge their reaction to reduced oxygen and can render them unconscious.

Now Oklahoma plans to use nitrogen in its death-penalty chamber.

Attorney General Mike Hunter and Corrections Director Joe Allbaugh announced the plan on Wednesday, saying an execution protocol will be developed for using nitrogen hypoxia, or inert gas inhalation.

If the plan and protocols withstand court scrutiny, Oklahoma would become the first state to use the method in executions. The specifics are still being worked out, but Hunter and Allbaugh said using the gas method would eliminate the key hurdles to lethal injections: delicate medical procedures that have gone awry and resulted in a botched execution, and the difficulty of obtaining lethal drugs that won’t cause suffering that violates the Eighth Amendment ban on cruel and unusual punishment.

“I believe in justice for victims and their families, and in capital punishment as appropriate for dealing with those who commit these crimes,” Hunter said at a news conference, adding he talked to families of murder victims about the decision. “Using an inert gas will be effective, simple to administer, easy to obtain and requires no complex medical procedures.”

Oklahoma Attorney General Mike Hunter and Corrections Director Joe Allbaugh announce their plan to use nitrogen gas in executions at a news conference at the State Capitol on Wednesday. Credit: Ben Botkin / Oklahoma Watch

But how the process will work, whether it will work as intended, and whether it will survive almost certain legal challenges and court scrutiny remain to be seen.

“Nobody has attempted this kind of execution before,” said Robert Dunham, executive director of the Death Penalty Information Center. “It’s too early to say at this point what will come of this because there is both a state law and federal court order that Oklahoma has to comply with.”

Calling the protocol “experimental,” he added, “It’s a very different story when you’re trying to put to death a person who wants to stay alive than somebody who’s seeking to have euthanasia or someone who dies from accidental ingestion.”

Oklahoma has not executed an offender since Jan. 15, 2015, when Charles Warner was put to death for the 2003 slaying of 11-month-old Adrianna Waller. Later that year, it was revealed that Warner’s execution had been carried out using the wrong drug – potassium acetate instead of potassium chloride, for stopping the heart. That came to light after authorities in late September 2015 abruptly canceled the execution of Richard Glossip upon discovering they were about to use the wrong drug. The incident culminated nearly 17 months of turmoil in Oklahoma’s death-penalty process, starting with the botched execution of Clayton Lockett in April 2014, in which he writhed and groaned on the execution table before dying.

An indefinite stay of all executions was sought while Oklahoma worked on developing new protocols.

The troubles also led to the creation of the Oklahoma Death Penalty Review Commission, a study group that in April 2017 recommended dozens of changes to the state’s criminal justice and execution system. Many have not been adopted, including a recommendation that there be an independent, third-party review of completed executions. On Wednesday, when asked about that proposal, Allbaugh responded, “Not necessary.”

Seventeen inmates are eligible for execution and have exhausted the appeal process. Forty-eight inmates are on death row.

“Instead of following the recommendations of the Oklahoma Death (Penalty) Review Commission, the attorney general and Department of Corrections took a different course by adopting this new method of execution,” Dale Baich, an attorney for 20 death row inmates in Oklahoma who have sued and are challenging the state’s execution protocols for lethal injection, said in an interview.

Referring to the nitrogen-gas method, Baich said, “Oklahoma is once again asking its citizens to trust its officials as they learn on the job through a new execution procedure and method.

“How can we trust Oklahoma to get this right when the state has the recent history that reveals a culture of carelessness and mistakes?”

Nitrogen’s introduction as a potential execution method in Oklahoma isn’t a surprise. In 2015, Oklahoma legislators passed and Gov. Mary Fallin signed into law a bill that allows nitrogen hypoxia as an execution method.

In assisted suicides, nitrogen hypoxia ends life by reducing the oxygen that is breathed in, sometimes with a hood or other device placed over the head.

“Nitrogen hypoxia has been studied as a means of suicide and as it relates to pilots for decades and its benefits are it’s not a complicated medical procedure, nor does it require pharmaceuticals that might be restricted in supply,” said Michael Copeland, an assistant professor of criminology at East Central University in Ada who testified at a legislative hearing about the issue in September 2014.

Unknowns remain, given that state officials only recently began developing the protocols. For example, officials don’t know what equipment will be used, although Allbaugh said that a mask for delivering the gas would be developed.

Allbaugh said he has been on a “mad hunt” for drugs but came up empty after searches took him to potential sources overseas. In the end, it’s impossible to guarantee the chain of custody needed for the drugs, he said.

It will be months before any potential execution takes place. The lawsuit that death row inmates have filed has an agreement that the state will not seek an execution date until 150 days after providing information about changes to the protocol.

The 150-day period doesn’t start until the protocol is developed, which is expected to take at least 90 days.

Mississippi has a law allowing nitrogen to be used in executions if the lethal injection method is unconstitutional or unavailable, according to the Death Penalty Information Center. Alabama legislators are considering a bill on the issue this year.

Reach reporter Ben Botkin at or (702) 418-6089.

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