- Witness describes Alabama’s first execution by nitrogen gasThe Hill
- Alabama AG calls first nitrogen gas execution ‘textbook,’ but witnesses say inmate thrashed in final momentsYahoo News
- A brief history of the death penaltyThe Telegraph
- Four minutes of convulsions: Kenneth Smith executed with nitrogen gasMontgomery Advertiser
- What happened at the nation’s first nitrogen gas execution: An AP eyewitness accountThe Associated Press