In the US, a man sentenced to death has been executed for the first time using a new nitrogen method. 58-year-old Kenneth Eugene Smith died on Thursday evening in a prison in the US state of Alabama using so-called nitrogen hypoxia, according to the Death Penalty Information Center, an organisation that tracks all executions nationwide. Alabama’s Attorney General Steve Marshall confirmed the execution on Thursday evening. During the procedure, a person inhales nitrogen through a face mask – the result is death from lack of oxygen. Human rights experts had previously complained that the method …