Alabama to carry out second nitrogen gas execution

Alabama is planning to execute convicted murderer Alan Miller in the second ever nitrogen-asphyxiation execution since the state pioneered the method in January.

Miller, 65, was convicted for the 1999 murders of three men, including two co-workers, in a shooting spree at two offices in Pelham, Alabama.

In January, Alabama executed Kenneth Smith, also convicted of murder, by nitrogen asphyxiation, the first use of a new execution method since lethal injections began in the US four decades ago.

The state called its new protocol "the most painless" execution method yet, and predicted that Smith would lose consciousness and suffocate within a few seconds of pure nitrogen flowing through an industrial-safety respirator mask strapped to his face.

That did not happen. Multiple witnesses, including five journalists and members of Smith's family, saw Smith heaving against his restraints and convulsing as the nitrogen flowed, and it appeared to take him several minutes to lose consciousness.

The administration of US President Joe Biden, a Democrat who promised to abolish the death penalty, said it was "deeply troubled" by the new method. It has been condemned by senior UN human rights officials, who say it may amount to torture or cruel and inhuman treatment.

Alabama has defended the method, with Attorney General Steve Marshall calling Smith's death a "textbook" execution.

After Smith's execution, Miller sued Alabama over fears its asphyxiation method could violate a constitutional ban on cruel and unusual punishments.

He sought assurances that the mask would be properly fitted and that its seal be tested to ensure no oxygen seeps in, prolonging his death or even averting it entirely and leaving him alive with brain damage.

His litigation ended in a confidential settlement, and his execution is scheduled for 6pm local time (midnight Irish time) at the Holman Correctional Facility in Atmore, Alabama.

The Alabama Department of Corrections has declined to say if it made any changes to its gassing protocol.

Alabama has offered to help others adopt nitrogen-asphyxiation executions, saying they are a simpler alternative for states struggling to find lethal-injection drugs.

Advocacy groups against capital punishment have long pressured pharmaceutical companies to forbid their drugs be used in executions, and have turned their attention to nitrogen suppliers and mask makers, including the maker of the Allegro Safety mask Alabama acquired for its executions.

Stephanie Boucher, a spokesperson for Allegro's parent company Walter Surface Technologies in Connecticut, said the company will not comment on the use of its masks in executions.

A spokesperson for Canadian private equity firm Onex Corp, which has a majority stake in Walter Surface, did not respond to requests for comment.