Officials said Kenneth Eugene Smith, 58, was pronounced dead at 8:25 p.m. at an Alabama prison after breathing pure nitrogen gas through a face mask. It marked the first time that a new execution method has been used in the United States since lethal injection, now the most commonly used method, was introduced in 1982. Alabama Gov. Kay Ivey said the execution was justice for the murder-for-hire killing of 45-year-old Elizabeth Sennett in 1988. MORE: https://www.wthr.com/article/news/nation-world/alabama-first-nitrogen-gas-execution-expected-thursday/507-4aa2755a-7347-43a3-9980-78925aa6d9c8