Atmore, Alabama - A man named Demetrius Frazier was put to death by nitrogen gas in Alabama on Thursday, the fourth use of the controversial execution method in the state.

Demetrius Frazier (52) was sentenced to death in 1996 for the 1991 murder of 40-year-old Pauline Brown, a mother of two, in the Alabama city of Birmingham.

Frazier was found guilty of breaking into Brown's apartment, raping her, and shooting her in the head. The jury voted 10-2 to recommend the death penalty.

According to court documents, Frazier, who is Black, accused the predominantly white jury during his trial of being racist.

Justice Alabama set to put Demetrius Frazier to death with controversial execution method

Frazier was previously convicted of rape and the 1992 murder of a 14-year-old girl, Crystal Kendrick, in Michigan, which does not have the death penalty. He was serving a life sentence there for Kendrick's murder and for two separate rape convictions.

Frazier was transferred to Alabama in 2011 and appeals seeking to have him sent back to Michigan to serve his life sentence were rejected.

His appeals claiming that the nitrogen gas method of execution amounts to cruel and unusual punishment were also denied.

Frazier was put to death at a prison in Atmore, Alabama, on Thursday. The Alabama Department of Corrections said he was pronounced dead at 6:36 PM Central Time.

Alabama carried out three executions by nitrogen asphyxiation last year and is the only state currently using the method. Other states use lethal injection.

The execution is performed by pumping nitrogen gas into a facemask, causing the prisoner to suffocate.

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United Nations experts appointed by the UN Human Rights Council have denounced the use of nitrogen gas, saying it "may amount to cruel, inhuman or degrading treatment, or even torture."

There were 25 executions in the US last year.

The death penalty has been abolished in 23 of 50 states, while three others – California, Oregon, and Pennsylvania – have moratoriums in place.

Three states – Arizona, Ohio, and Tennessee – that had paused executions have recently announced plans to resume them.

President Donald Trump is a proponent of capital punishment, and on his first day in the White House, he called for an expansion of its use "for the vilest crimes."