The death penalty debate in the US heated up once again after Alabama executed a prisoner using the Nitrogen Gas Execution method, with the state's attorney general vowing to use that method again in future executions.

On Thursday, Alabama became the first state to use nitrogen hypoxia, also known as nitrogen gas execution, to execute a convicted criminal, with convicted murderer Kenneth Eugene Smith making history as the first person to die from that method.

In a nitrogen gas execution, the nitrogen gas causes asphyxiation by forcing an individual to inhale pure nitrogen or lethally high concentrations of it via a gas mask, according to CBS News. Smith reportedly convulsed as he was suffering asphyxiation during his execution.

"What occurred last night was textbook," Alabama Attorney General Steve Marshall told reporters after the execution. "As of last night, nitrogen hypoxia as a means of execution is no longer an untested method. It is a proven one."

Smith was given the then-experimental execution method after surviving a botched lethal injection execution back in 2022. He reportedly requested the method of death even though his attorneys argued that he was being used as a "test subject."

During his execution, protesters gathered to decry the use of the death penalty and rallied against the use of experimental execution methods, such as nitrogen gas execution. Human rights advocates also railed against Alabama's decision to execute criminals.

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Who Was Alabama Man Who Was Executed Via Nitrogen Gas?

Kenneth Eugene Smith is a convicted killer who has been on death row since 1990 and was originally supposed to be executed in 2022. In his last words, he reportedly said, "Tonight Alabama caused humanity to take a step backward. I'm leaving with love, peace, and light. Thank you for supporting me. Love all of you."

He was convicted of the 1988 murder of Elizabeth Dorlene Sennett, who was married to a local minister who was having an affair and was in debt, according to PEOPLE magazine. He was supposed to be executed via electrocution before it was changed to lethal injection, which he survived.

His victim's husband, Charles Sennett, reportedly hired Smith to kill Elizabeth and to make it look like a burglary gone wrong. Smith and another accomplice, who was previously executed in 2010, killed her after stabbing her multiple times. Sennett himself committed suicide soon after.

Death Penalty Debate Rages After Successful Alabama Nitrogen Gas Execution

Meanwhile, Smith's supporters expressed alarm at how the execution happened, as the Associated Press reported that he convulsed in seizure-like spasms for at least two minutes. He was shaking so much that his gurney was also visibly shaking.

Death penalty opponents said that Smith's execution did not match the state's promise of a quick and painless death, including his spiritual adviser, Reverend Jeff Hood, who attended the execution.

"We didn't see somebody go unconscious in 30 seconds. What we saw was minutes of someone struggling for their life," the preacher told the AP.

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This article is owned by Latin Post.

Written by: Rick Martin

WATCH:Witness describes final moments of Alabama prisoner Kenneth Smith killed with nitrogen gas - AL.com