Execution of Kenneth Eugene Smith

The execution of Kenneth Eugene Smith (July 4, 1965 – January 25, 2024) took place in the U.S. state of Alabama by means of nitrogen hypoxia. It was the first execution in the world to use this particular method.

Smith was convicted of the March 18, 1988, murder-for-hire of Elizabeth Sennett in Colbert County, Alabama. Charles Sennett Sr., Elizabeth's husband, recruited Billy Gray Williams to murder his wife. Williams in turn recruited Smith and John Forrest Parker to assist in the murder. Smith and Parker carried out the murder and stabbed Elizabeth Sennett to death at her home in Colbert County. A week after Elizabeth's murder, Charles Sennett Sr. killed himself when he learned he was a suspect in the murder. Billy Gray Williams was sentenced to life imprisonment without the possibility of parole and died in prison in November 2020. Smith and John Forrest Parker were both sentenced to death. Parker was executed via lethal injection in June 2010.

In November 2022, Smith was scheduled to be executed by lethal injection, but the execution was stayed after the execution team was unable to connect the intravenous lines to Smith in the time available before the expiration of the death warrant issued by the Alabama Supreme Court. As part of a settlement between the state and Smith, the state agreed not to pursue Smith's execution by lethal injection (the default primary method of execution in Alabama) and instead utilize a secondary novel method of execution, nitrogen hypoxia. After losing his final appeal to the U.S. Supreme Court, Smith was ultimately executed by nitrogen hypoxia on January 25, 2024, becoming the first person to be executed by that method.