Why Oklahoma is using nitrogen gas as a backup to lethal injections

The future of executions in Oklahoma may not be lethal injections, but rather a gas that asphyxiates prisoners to death.

On Friday, Oklahoma Gov. Mary Fallin authorized the use of nitrogen hypoxia as a backup for the death penalty if its primary method of executions, lethal injection, is ruled unconstitutional or becomes unavailable due to a drug shortage. The gas will be applied through a mask or medical-grade o