By Darren Lyn
HOUSTON, US (AA) – The US state of Alabama on Thursday night executed its second death row inmate by the controversial method known as nitrogen hypoxia.
Alan Eugene Miller, 59, was strapped to a gurney and administered nitrogen gas through a mask, in which the procedure has the inmate inhale the gas until it depletes all of the oxygen from his system and he dies.
Critics have deemed the method cruel, painful and torturous, with the United Nations condemning it as "nothing short of state-sanctioned torture."
Miller shook and trembled on the gurney for about two minutes, with his body at times pulling against the restraints, according to a reporter who was sanctioned to witness the procedure. Miller also spent about six minutes with periodic gulping breaths before he passed away.
Alabama Department of Corrections Commissioner John Hamm said at a news conference that the two minutes of shaking was to be expected.
"Everything went according to plan and according to our protocol, so it went just as we had planned," said Hamm.
Miller was sentenced to death in 2000 for the 1999 killings of three men. He claimed his innocence all the way until the end.
"I didn’t do anything to be in here," Miller said in his final words through the mask that covered his face.
Alabama Gov. Kay Ivey heralded the execution as closure for the victims' families and emphasized that the nitrogen gas death penalty procedure was the method that Miller chose instead of lethal injection.
"Tonight, justice was finally served for these three victims through the execution method elected by the inmate," Ivey said in a statement. "His acts were not that of insanity, but pure evil. Three families were forever changed by his heinous crimes, and I pray that they can find comfort all these years later."
Alabama executed what is believed to be its first death row inmate by nitrogen hypoxia earlier this year on Jan. 25.
Kenneth Smith, 58, was sentenced to death for his part in a murder-for-hire plot. During his nitrogen gas procedure, he also "shook and writhed on a gurney" with several minutes of deep breathing before he died, according to a reporter who witnessed his execution.
Proponents of nitrogen hypoxia said a person would likely lose consciousness shortly into the procedure, making it more humane than other execution methods. But doctors have said that they could not specifically pinpoint if or when a person would lose consciousness when exposed to high doses of nitrogen gas.
Alabama is the only US state that has used nitrogen hypoxia for its death penalty. Three other states -- Louisiana, Oklahoma and Mississippi -- have also authorized the nitrogen gas method but have not yet used it for executions.