Nitrogen gas execution was "textbook" and will be used again, Alabama attorney general says

The execution of convicted murderer Kenneth Eugene Smith using nitrogen hypoxia was "textbook," Alabama's attorney general Steve Marshall said in a news conference on Friday. 

The execution was carried out on Thursday night and marked the first time nitrogen hypoxia, a process that aims to cause asphyxiation by forcing an individual to inhale pure nitrogen or lethally high concentrations of it through a gas mask, was used to execute someone. 

"What occurred last night was textbook," Marshall said. "As of last night, nitrogen hypoxia as a means of execution is no longer an untested method. It is a proven one."