Missouri is only one of four states that retains the gas chamber as its secondary method of execution.
Executions by lethal gas were carried out in an airtight chamber where the condemned would be strapped to a chair. A lever dropped cyanide pellets into a crock containing sulfuric acid that was situated under the chair. The lethal gas would asphyxiate the person.
The last execution in the United States by gas chamber was carried out in Arizona in 1992. According to the Death Penalty Information Center it was a botched execution. The person took 10-12 minutes to expire and was thrashing violently, moaning, gasping for air. One reporter witnessing the execution wrote….”This was a violent death…an ugly event. We put animals to death more humanely.”
If Missouri were to reinstate the gas chamber, there is little doubt that it would be challenged in court as violating the Constitution’s ban on “cruel and unusual punishment”. Such torture has no place in a civilized society.