Lawyers failed to persuade courts to stay the execution, arguing procedure amounted to cruel and unusual punishment
Alabama has carried out the first execution of a death row inmate in the US using nitrogen gas, an untested procedure which the prisoner’s lawyers had argued amounted to a form of cruel and unusual punishment banned under the US constitution.
Kenneth Smith, 58, was pronounced dead at 8.25pm on Thursday evening at an Alabama prison after breathing pure nitrogen gas through a face mask to cause oxygen deprivation.