Alabama man becomes first person in US to be executed by nitrogen gas

Kenneth Smith was a contract killer who was executed by nitrogen hypoxia

An Alabama death row inmate has been put to death by nitrogen gas in the first known execution of its kind. Kenneth Smith was pronounced dead at 8.25pm on Thursday (local time) after breathing pure nitrogen gas through a face mask.

His case marks the first known execution by nitrogen hypoxia, which his lawyers had argued amounted to a form of “cruel and unusual punishment”. Death by nitrogen gas is an untested procedure, and its opponents say it can cause unnecessary suffering.

Smith, 58, was a contract killer who had been on the death row since 1996. He was convicted for the murder of Elizabeth Sennett in 1989, according to BBC.

Earlier on Thursday, the US Supreme Court had denied Smith’s last minute appeal to halt the execution. A federal court had also declined to halt the execution on Wednesday even as his attorneys argued that death by nitrogen amounted to cruel and unusual punishment which is banned by the US Constitution.

Alabama is only one of three US states that has approved execution by nitrogen.

In 2022, Smith had survived the state’s attempt to execute him with lethal injection as they could not find a vein. After the failed attempt, Smith had requested execution by nitrogen gas, asking Alabama not to attempt another execution by lethal injection.

“The execution was lawfully carried out by nitrogen hypoxia, the method previously requested by Mr. Smith as an alternative to lethal injection. At long last, Mr. Smith got what he asked for, and this case can finally be put to rest," said Alabama Governor Kay Ivey.

According to BBC, the drugs used in lethal injection have become more difficult to procure, which in turn has led to a nation-wide fall in the number of executions.

Local news reports suggest that Smith’s execution took 22 minutes. “He appeared to shake and writhe on the gurney,” reported NBC, and sometimes seemed to be struggling against the restraints. This was followed by several minutes of heavy breathing until he lost consciousness.