Alabama death row inmate executed with nitrogen gas, nation's first by a new method in 42 years

Alabama has carried out the nation’s first execution by nitrogen asphyxiation.
Pay-for-hire murderer Kenneth Smith stabbed a preacher’s wife to death in 1988. The state tried to execute him once through lethal injection, which failed. This time, it used the novel method of death by nitrogen hypoxia.
The courts rejected Smith’s lawyers' appeals, which were based on the idea that the nitrogen process is so unknown that it constitutes cruel and unusual punishment. The state says it should cause relatively "painless" death within minutes.