Alabama carries out the second nitrogen gas execution in the United States

The US state of Alabama has executed Alan Eugene Miller – the second American ever killed by inhaling nitrogen gas.

Miller, 59, was sentenced to death for the consecutive 1999 murders of Lee Holdbrooks, Christopher Scott Yancy and Terry Lee Jarvis.

His execution is the fifth in the United States in a week – the largest use of the death penalty in more than two decades.

Also on Thursday, Emmanuel Littlejohn received a lethal injection in Oklahoma after the state's governor rejected a last-minute request for clemency.

Miller's execution is the 18th this year – and seven more are scheduled for the remaining three months of 2024.

According to the non-profit organization Death Penalty Information Center (DPIC), there are also 1,600. Execution in the United States since the death penalty was reinstated by the country's highest court in 1976.

Freddie Owens was executed last Friday in South Carolina, while Marcellus Williams was executed in Missouri and Travis Mullis in Texas on Tuesday.

DPIC data also suggests that July 2003 was the last time so many prisoners were sentenced to death in seven days.

Experts told US media that the timing was purely coincidental, due to changes in the execution schedule due to previously botched executions and legal challenges.

For years, executions across the country have been declining. According to DPIC, 35 states have either abolished or not used the death penalty for at least a decade.

But the number of executions has increased in the last three years, especially in Texas, Missouri, Alabama and Florida.

Last year, 24 people were executed, up from 18 in 2022 and 11 in 2021.

Miller, 59, was sentenced to death for the consecutive workplace murders of Holdbrooks, Yancy and Jarvis in 1999.

He was originally scheduled to die in 2022, but was granted a reprieve when officials struggled to connect an intravenous line through which his fatal injection would be administered.

Earlier this year, the Alabama state Supreme Court allowed Miller to be executed by nitrogen hypoxia, a method in which an inmate breathes nitrogen gas through a fitted mask until his body is deprived of oxygen.

Alabama is one of only three states that authorize this form of death penalty and carried out the first such execution last January.

The nitrogen-induced killing of Kenneth Eugene Smith was described as “textbook” by the attorney general, but critics said it was painful and inhumane.

“In Alabama, we will not deny justice to the victims of heinous murders,” Attorney General Steve Marshall said in a statement.

“Tonight, despite misinformation campaigns by political activists, foreign lawyers and biased media outlets, the state once again proved that nitrogen hypoxia is both humane and effective.”

Littlejohn, 52, was sentenced to death for his role in a 1992 robbery that ended with the murder of supermarket owner Kenneth Meers.

Both Littlejohn and his accomplice Glenn Bethany were charged and convicted in the incident, but Littlejohn's lawyers argued that it was not he who fired the fatal shot and that jurors were confused about their sentencing options.

Littlejohn was 20 at the time of his crime and his lawyers argued that a robbery-related killing should not carry the death penalty

Two jurors from his 1994 conviction and 2000 resentencing submitted affidavits as part of his latest clemency petition saying they did not believe he should be executed.

But prosecutors said two teenage witnesses claimed it was Littlejohn, not Bethany, who pulled the trigger and killed Meers.

The Oklahoma Pardon and Parole Board voted 3-2 last month to spare Littlejohn's life and commute his sentence to life in prison without parole.

Gov. Kevin Stitt declined to grant the reprieve, saying, “A jury found him guilty and sentenced him to death. “As law and order governor, it is difficult for me to unilaterally overturn this decision.”

Littlejohn's mother, daughter and spiritual advisor all witnessed his execution by lethal injection.