An Alabama inmate found guilty of murdering a hitchhiker 30 years ago on Thursday became the third person in America to be executed using nitrogen gas, furthering the ongoing debate about whether the method is an inhumane way to carry out death penalty sentences.

Carey Dale Grayson is set to die by nitrogen hypoxia after being convicted of killing 37-year-old hitchhiker Vickie Deblieux in 1994.

Alabama began using nitrogen gas earlier this year to carry out some executions. The method involves placing a respirator gas mask over the face to replace breathable air with pur

An Alabama man sentenced to death for the murder of a hitchhiker back in 1994 became the third person put to death by nitrogen hypoxia on Thursday evening amid controversy and outcry at the execution

Grayson’s three accomplices managed to escape execution because they were under 18 at the time of Deblieux’s murder

ATMORE − The State of Alabama executed Carey Dale Grayson by nitrogen gas hypoxia Thursday evening for the brutal 1994 Jefferson County murder of a hitchhiker. It was Alabama's sixth execution for the year and the third in two months.

Prison officials in Alabama have executed convicted murderer Carey Dale Grayson, marking the state's sixth death sentence and third using the nitrogen gas method so far this year.

The execution is the 22nd in the U.S. this year and the sixth in Alabama, which has put three of the men to death using nitrogen gas.