Demetrius Terrance Frazier was the fourth person executed in the United States using nitrogen hypoxia, which involves replacing breathable air with pure nitrogen gas

An Alabama death row inmate was executed Feb. 6 by nitrogen hypoxia at William C. Holman Correctional Facility, just outside Atmore, according to the Alabama Department of Corrections. Public Information Officer Kelly Betts said in a release that Demetrius T.

An Alabama death row inmate who raped and murdered a woman in 1991 was executed this week using nitrogen gas, making him the fourth person in the U.S. to die by the controversial method.