Alabama plans to use untested execution method: What is nitrogen hypoxia?

Alabama says it could soon be ready to use a new, untried execution method called nitrogen hypoxia. The move comes as states that carry out the death penalty have increasingly encountered difficulty in obtaining drugs that have been used in lethal injections.

States are considering methods other than lethal injection as execution drugs have become more scarce

Holman Prison in Atmore, Ala., is shown on Jan. 27. Alabama, one of a small number of states carrying out executions of death row inmates, could be the first in the U.S. to employ nitrogen hypoxia in its execution method. (Jay Reeves/The Associated Press)

Alabama told a federal judge this week that it could soon be ready to use a new, untried execution method called nitrogen hypoxia to carry out a death sentence.

The disclosure came Monday at a court hearing over inmate Alan Miller's request to block his scheduled Sept. 22 execution by lethal injection. Miller maintains that prison staff lost paperwork he returned in 2018 requesting nitrogen hypoxia, an execution method that the state has authorized but never used.

James Houts, a deputy state attorney general, said the method could be available as soon as next week. However, a final decision on when to use the new method would be up to the state's corrections commissioner. 

Here is what is known about nitrogen hypoxia:

Has it ever been employed in an execution?

No state has used nitrogen hypoxia to carry out a death sentence.

In 2018, Alabama became the third state — along with Oklahoma and Mississippi — to authorize the untested use of nitrogen gas to execute prisoners. Some proponents have theorized that nitrogen hypoxia would be a simpler and more humane execution method. 

How would it work in an execution?

This undated photograph shows inmate Alan Eugene Miller, who was convicted of capital murder in a workplace shooting that killed three men in 1999. Miller says he previously requested nitrogen hypoxia be used in his execution. (Alabama Department of Corrections/The Associated Press)

Nitrogen makes up 78 per cent of the air inhaled by humans and is harmless when inhaled with oxygen. The theory behind the execution method is that changing the composition of the air to 100 per cent nitrogen would deprive the person of the oxygen needed to maintain bodily functions.

Trip Pittman, a former Republican lawmaker in Alabama who sponsored the 2018 legislation, theorized it would be similar to how aircraft passengers pass out when a plane depressurizes.

The state has released little information about the proposed method. Most of the available information has come from court proceedings. The Alabama Department of Corrections told a federal judge last year that it had completed a "system" to use nitrogen gas but did not describe it.

During a Sept. 11 court hearing, a lawyer for the state said they asked Miller if he would agree to be fitted with a mask, an indication that the state may intend to place a face mask over the inmate's nose and mouth.

Why is the new method being considered?

After capital punishment was reinstated in the U.S. in 1976, most executions were carried out by electrocution, with some others by gas chamber, hanging or firing squad. Lethal injection was carried out for the first time in 1982 and became the dominant method, with officials believing it to be a more humane and efficient method. According to the non-profit Death Penalty Information Center (DPIC), 1,370 people have been executed via lethal injection, representing 88 per cent of all executions since 1976.

States began proposing nitrogen hypoxia as an alternate execution method because of the difficulty obtaining lethal injection drugs, as in recent years pharmaceutical companies and their shareholders balked at selling their product to states for use in capital punishment.

Other states have even reconsidered the possibility of using a firing squad or electrocution, though legal challenges have prevented those methods from being used again.

What are the concerns?

Critics have likened the untested method to human experimentation.

"It is completely untested," said Robert Dunham, executive director of the Death Penalty Information Center. No state has publicly released a protocol describing how it would work.

While proponents have theorized it would be quick and painless, Dunham noted that states once said the same thing about the electric chair.

The American Veterinary Medical Association's euthanasia guidelines say inert gas hypoxia is acceptable, under certain conditions, for the euthanasia of chickens, turkeys and pigs, but is not recommended for other mammals such as rats.

What happens next?

Alabama is working on finalizing a protocol for using nitrogen hypoxia. The steps must be added to the existing state protocol that describes the procedures for an execution using the electric chair or lethal injection.

He said Alabama's prison commissioner has the final decision on when to allow its use. Litigation is expected if the state decides to go forward with the method. 

What's the state of the death penalty in the U.S?

Currently, 27 states allow for capital punishment, though governors of three of them have issued a moratorium on the practice for as long as their tenures last.

Of the remaining 24, only a small number have consistently carried out executions in recent years. Most states have seen the consequences of overzealous or flawed prosecutions, with 185 prisoners "released from death row with evidence of their innocence," according to DPC.

After capital punishment was reinstated in the U.S. in 1976, the most executions carried out in a single year occurred in 1999, a total of 98 inmates. The total has been fewer than 40 in every year since 2013, falling to a record-low 11 in 2021. So far this year, there have been 10 executions overall, carried out in Alabama, Florida, Missouri, Oklahoma and Texas.

During Donald Trump's administration, 13 executions were carried out of inmates given federal death sentences, the first carried out at the federal level since 2003. Attorney General Merrick Garland of President Joe Biden's administration ordered a pause on federal executions last year until a full review of the practice could be completed.

With files from CBC News