In a recent ruling, the Supreme Court has denied the request of Kenneth Smith, a death row inmate, to change his method of execution from lethal injection to nitrogen hypoxia. Smith argued that executing him through nitrogen hypoxia would violate his right to be free from cruel and unusual punishment under the Eighth Amendment.

The brief court order provided no further explanation and there were no public dissents from the justices. However, Smith still has a separate claim pending in federal court that could potentially halt his execution.

Smith's legal team asserted that nitrogen hypoxia has never been employed for execution in the United States. According to the Death Penalty Information Center, the last time lethal gas was used to carry out an execution was in 1999.

This isn't the first time Smith has faced legal challenges regarding his execution. The Supreme Court had rejected a previous attempt to execute him by lethal injection in May of last year. Smith had argued that the state's struggle to insert an intravenous line before the deadline raised doubts about their ability to use the new method effectively. Consequently, the execution was called off.

Smith's lawyers contended that making another attempt to execute him would be considered "cruelly willful" and tantamount to torture. They submitted an emergency request emphasizing that Alabama's execution efforts, if carried out, would mark just the second time in US history that a state pursues a second execution attempt following a failed one.

Responding to Smith's claims, Alabama Attorney General Steve Marshall pointed out previous statements made by Smith where he expressed a preference for lethal gas as the method of execution. Marshall argued that the allegations raised by Smith should not serve as grounds for relief, as he had already litigated successfully for the method of execution he is set to receive.

Throughout the legal process, Smith's pleas were rejected by Alabama state courts, including the Alabama Court of Criminal Appeals. When the Alabama Supreme Court declined to hear his case, Smith turned to the US Supreme Court in search of relief.

Nitrogen hypoxia, the alternative execution method Smith sought, induces death by depriving the inmate of oxygen and replacing it with nitrogen gas. According to the state's execution protocol, a mask would be placed over the inmate's face, and nitrogen gas would be administered until death. Oklahoma and Mississippi are two other states that have also approved the use of nitrogen hypoxia.

While most states that administer capital punishment usually rely on lethal injection, challenges to obtaining the necessary lethal drugs have posed significant obstacles. Smith's legal team and opponents of the death penalty have highlighted potential risks associated with the use of nitrogen hypoxia, such as the possibility of leaving the inmate in a vegetative state or the risk of choking on vomit. There are also concerns about potential gas leaks and the safety of those present in the execution chamber.

The Supreme Court, which currently holds a conservative majority with a 6-3 split, tends to be skeptical of last-minute stay requests by death row inmates and has made it more difficult for prisoners to challenge their execution methods. In a 2019 ruling, the Court denied a convicted murderer's request to die by lethal gas instead of lethal injection based on a rare medical condition, asserting that prisoners are not guaranteed a painless death.

Critics of last-minute claims made by defense lawyers argue that such tactics are employed solely to delay executions, dubbing it a "guerrilla war against the death penalty," as referenced by Justice Samuel Alito during a 2015 oral argument.

While the denial of Smith's request brings him closer to his scheduled execution, his ongoing federal claim may still present a legal avenue to challenge his sentence and the method of execution.

As the case unfolds, legal experts and the public remain engaged, watching how these ongoing battles and debates surrounding capital punishment will impact the future trajectory of the death penalty in the United States.