Houston: The state of Alabama on Thursday night completed the country's first execution using nitrogen gas asphyxiation.
Inmate Kenneth Smith, a 58-year-old convicted murderer, was put to death at 8:25 pm local time at an Alabama prison after breathing pure nitrogen gas through a face mask to cause oxygen deprivation, authorities said.
US Supreme Court had declined to halt first nitrogen gas execution in this case.
The Alabama has called its new protocol "the most painless and humane method of execution known to man." (Agencies)
