Alabama execution using nitrogen gas, the first ever, again puts U.S. at front of death penalty debate

A man who was paid $1,000 to kill an Alabama woman more than 30 years ago was put to death with pure nitrogen gas, a first-of-its-kind execution that again placed the United States at the forefront of the debate over capital punishment.

Kenneth Eugene Smith, 58, appeared to shake and convulse at the start before being pronounced dead at 8:25 p.m. Thursday at an Alabama prison after breathing the gas through a face mask to cause oxygen deprivation. It marked the first time a new execution method was used in the U.S. since 1982, when lethal injection was introduced and later became the most common method.

The execution took about 22 minutes from the time between the opening and closing of the curtains to the viewing room. 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.

"Tonight Alabama causes humanity to take a step backwards," Smith said in a final statement. "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 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," Ivey said in a statement. "I pray that Elizabeth Sennett's family can receive closure after all these years dealing with that great loss."

Mike Sennett, the victim's son, said Thursday night that Smith "had been