US: convicted murderer executed with nitrogen gas; first time capital punishment method used in world

Alabama executed a convicted murderer with nitrogen gas Thursday, putting him to death with a first-of-its-kind method that once again placed the U.S. at the forefront of the debate over capital punishment. The state said the method would be humane, but critics called it cruel and experimental.

Officials said Kenneth Eugene Smith, 58, was pronounced dead at 8:25 p.m. at an Alabama prison after breathing pure nitrogen gas through a face mask to cause oxygen deprivation. It marked the first time that a new execution method has been used in the United States since lethal injection, now the most commonly used method, was introduced in 1982.

The execution took about 22 minutes, and Smith appeared to remain conscious for several minutes. For at least two minutes, he appeared to shake and writhe on the gurney, sometimes pulling against the restraints. That was followed by several minutes of heavy breathing, until breathing was no longer perceptible.

In a final statement, Smith said: “Tonight Alabama causes humanity to take a step backwards. ... I’m leaving with love, peace and light.”

He made the “I love you sign” with his hands toward family members who were witnesses. “Thank you for supporting me. Love, love all of you,” Smith said.

Alabama Gov. Kay Ivey said afterward that the execution was justice for the murder-for-hire killing of 45-year-old Elizabeth Sennett in 1988.

“After more than 30 years and attempt after attempt to game the system, Mr. Smith has answered for his horrendous crimes. ... I pray that Elizabeth Sennett’s family can receive closure after all these years dealing with that great loss,” Ivey said in a statement.

The state had previously attempted to execute Smith in 2022, but the lethal injection was called off at the last minute because authorities couldn’t connect an IV line.

The execution came after a last-minute legal battle in which his attorneys contended the state was making him the test subject for an experimental execution method that could violate the constitutional ban on cruel and unusual punishment. Federal courts rejected Smith’s bid to block it, with the latest ruling coming Thursday night from the U.S. Supreme Court.

The state had predicted the nitrogen gas would cause unconsciousness within seconds and death within minutes. State Attorney General Steve Marshall said late Thursday that nitrogen gas “was intended to be — and has now proved to be — an effective and humane method of execution.”

Asked about Smith's shaking and convulsing on the gurney, Alabama corrections Commissioner John Q. Hamm said they appeared to be involuntary movements.

“That was all expected and was in the side effects that we’ve seen or researched on nitrogen hypoxia,” Hamm said. “Nothing was out of the ordinary from what we were expecting.”