In a historic move by the state of Alabama, convicted murderer Kenneth Smith, 58, became the first inmate in the world to be executed with nitrogen gas. The US Supreme Court had declined a legal bid to halt his sentence, and his official time of death was 8.38pm on Thursday, after the execution that took about 22 minutes. Witnesses described Smith's horrific experience, stating that he appeared to remain conscious for several minutes and appeared to shake and writhe before breathing was no longer perceptible.

The use of nitrogen gas as a method of execution has sparked controversy, with critics arguing that it is cruel and experimental. Smith's final statement before the execution was, "Tonight Alabama causes humanity to take a step backwards... I'm leaving with love, peace and light." Following the controversial execution, Alabama state Governor, Kay Ivey said, "Mr Smith has answered for his horrendous crimes, after more than 30 years and attempt after attempt to game the system."

The method of nitrogen hypoxia was previously requested by Mr Smith as an alternative to lethal injection. Human rights and legal issues have been raised regarding Smith's execution, with the United Nations’ human rights commissioner branding the method as "torture" and urging the state not to use it. Moving forward, it remains to be seen how the use of nitrogen gas as a method of execution will be received by the public and legal system, as its effectiveness and ethics are called into question.