Alabama executed a convicted murderer with nitrogen gas on Thursday, putting him to death with a new method that once again put the US 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 8:25pm 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 me

Alabama executed a convicted murderer with nitrogen gas on Thursday, putting him to death with a new method that once again put the US 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 8:25pm 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.