The U.S. Supreme Court on Thursday night blocked Alabama’s planned execution of Jeffery Lee, preventing the state from using nitrogen gas as the method of execution. The court issued an unsigned order without explanation, denying a last-minute appeal from Alabama officials after lower courts ruled the use of nitrogen hypoxia was “likely unconstitutional” in this case.

Lee, 49, was scheduled to be executed at 6 p.m. Thursday for a double murder committed in 1998 near Selma, Alabama. He was convicted of fatally shooting Jimmy Ellis, a pawnshop owner, and Ellis’s former wife, Elaine Thompson. A third person was wounded but survived. The jury initially recommended a life sentence, but the trial judge imposed the death penalty through a judicial override, a practice Alabama eliminated in 2017.

Alabama became the first state to employ nitrogen hypoxia for an execution this year, with Lee set to be the eighth inmate in the state and ninth nationally to die by this method. The procedure involves the inmate inhaling pure nitrogen gas, which deprives the body of oxygen, leading to unconsciousness and death. Proponents of the method argue it is quicker and less painful than lethal injection, which has been fraught with difficulties due to drug shortages.

However, Lee and his lawyers have challenged the use of nitrogen hypoxia, citing reports of inmates struggling and gasping during executions. Lee proposed execution by firing squad, which he contended would be less painful and more humane. In response, state officials said Alabama lacks the protocol, staffing, and legislative approval to carry out death by firing squad, though lethal injection and electrocution remain legal options.

Judge Emily Marks of the U.S. District Court for the Middle District of Alabama originally allowed the execution to proceed, but the 11th Circuit Court of Appeals reversed that decision and remanded the case. Following additional review, Judge Marks granted a preliminary injunction blocking the use of nitrogen hypoxia, agreeing that firing squad presented a lower risk of severe pain. The 11th Circuit upheld her ruling on Wednesday night.

The Supreme Court’s intervention prevented Alabama from proceeding with Lee’s execution by nitrogen gas but provided only a temporary reprieve. Governor Kay Ivey expressed disappointment at the decision but emphasized commitment to ultimately carrying out justice for the victims.

Attorney General Steve Marshall defended the use of the death penalty, underscoring the state's obligation to enforce court sentences and honor victims. Meanwhile, supporters of Lee and death penalty opponents hailed the ruling as a significant step toward overturning nitrogen hypoxia as a constitutional method of execution.

The implementation of nitrogen hypoxia has been controversial. Witnesses to recent executions reported inmates convulsing and struggling for breath for extended periods, raising questions about the method’s humanity. The case has intensified scrutiny of evolving execution protocols as states seek alternatives amid challenges with lethal injection drugs.

Reverend Jeff Hood, a spiritual adviser to Alabama death row inmates, described the Supreme Court’s stay as a hopeful sign that the continued use of nitrogen gas may soon end. The legal dispute over execution methods in Alabama highlights broader national debates over the constitutionality and ethics of capital punishment practices.