First U.S. nitrogen-gas execution

The U.S. state of Alabama is poised to use gas in a planned execution, the first state to attempt nitrogen hypoxia amid a shortage of barbiturates used in lethal injection executions 

Jan 25, 2024: Kenneth Eugene Smith, convicted for murder- for-hire in 1988, is scheduled to be executed by gas

2012: EU imposes ban on “execution drug” exports

2014: States stop use of midazolam following executions in Oklahoma, Ohio and Arizona in which prisoners appear to suffer

Execution: Inmate placed on gurney. Pulse oximeter measures oxygen levels in blood, electrocardiograph (ECG) records electrical signal from heart

Mask: Strapped to inmate’s face

Gas: Nitrogen is administered into mask for either 15 minutes or five minutes following flatline indication on ECG, whichever is longer

Risks: Seal on mask might break allowing in oxygen. Scenario could induce stroke or leave inmate in permanent vegetative state
                  
 
       
Sources: NBC News, Reuters Pictures: Getty Images, Alabama prison © GRAPHIC NEWS