On January 25, 2024, Alabama executed Kenneth Smith using nitrogen gas—the first time any government in the United States used that method. Smith, who had survived a botched lethal injection attempt in 2022, convulsed on the gurney for several minutes before dying. The execution reignited a decades-old legal question: does the Eighth Amendment ban specific ways of killing a condemned prisoner?
The Supreme Court has set a high bar for challenging execution methods. In Glossip v. Gross (2015) and Bucklew v. Precythe (2019), the Court ruled that an inmate must identify a "feasible, readily implemented" alternative that would "significantly reduce a substantial risk of severe pain." Simply arguing that a method is painful is not enough—the prisoner has to propose something better.
The Court has never declared a specific method of execution categorically unconstitutional, though it banned public and deliberately torturous methods in earlier eras. Today, lethal injection remains the primary method in most death-penalty states, but drug shortages have pushed states toward alternatives: firing squads in Utah, South Carolina, and Mississippi; electrocution in several Southern states; and nitrogen hypoxia in Alabama. Each new method invites fresh litigation over whether it crosses the constitutional line.