An man convicted of murdering a woman after breaking into her apartment as she slept was put to death Thursday evening in Alabama in the nation’s fourth execution using nitrogen gas.

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

ATMORE, Ala. — Alabama executed a man on Thursday who was convicted in the 1991 rape, robbery and murder of a Birmingham woman, becoming the fourth person put to death by nitrogen gas.