How have other states implemented nitrogen hypoxia or firing squad executions, and what legal challenges have followed?
Executive summary
Several U.S. states have recently adopted or proposed nitrogen hypoxia and firing squad executions as alternatives to lethal injection amid drug shortages and litigation; Alabama and Louisiana have used nitrogen hypoxia, while multiple states authorize firing squads and some have moved to make it a default option, and each adoption has provoked a wave of constitutional and statutory challenges focusing on Eighth Amendment cruelty claims, state constitutional punishment clauses, and procedural disputes [1] [2] [3] [4].
1. How states put nitrogen hypoxia on the books and into practice
Nitrogen hypoxia—forcing an inmate to breathe pure nitrogen until oxygen deprivation causes death—was authorized by several legislatures beginning in the 2010s and expressly adopted by states including Oklahoma , Alabama , Mississippi, Arkansas and Louisiana in later sessions, with Alabama becoming the first to actually carry out executions by this method in 2024 and Louisiana following in 2025 [5] [2] [6] [1]. Legislatures framed nitrogen as a solution to unavailable lethal-injection drugs and as a supposedly “humane” or pragmatic option; official protocols described masks or hoods delivering nitrogen while the condemned lay on a gurney, but medical experts and veterinary authorities have criticized the method and the term “nitrogen hypoxia” as not grounded in established humane medical practice [5] [4].
2. Where and how firing squads re-emerged in statute and policy
Firing-squad provisions have resurfaced in a number of states as a fallback when lethal-injection drugs or protocols faltered; by mid‑2025 five states authorized firing squads (Idaho, Mississippi, Oklahoma, South Carolina, and Utah), and Idaho moved further to make the firing squad the primary execution method under new law taking effect in 2026 [3]. Other legislatures — including in 2025 and 2026 sessions — have debated or passed bills to add firing squads alongside lethal injection and nitrogen gas, often explicitly citing difficulties obtaining drugs and prior botched executions as drivers for change [2] [7] [3].
3. Immediate legal fights and the Supreme Court backdrop
Adoption of novel methods triggered rapid litigation. Challenges have invoked the Eighth Amendment’s ban on cruel and unusual punishment and state constitutional limits on methods of punishment, and litigants sought stays, injunctions, and evidentiary hearings to probe how these methods would be administered; the U.S. Supreme Court has weighed in intermittently, declining to halt some planned nitrogen executions while cautioning about evidentiary gaps, and lower courts have both allowed and enjoined uses depending on record-specific findings [4] [8] [9]. Courts have applied precedents from Glossip and Bucklew, requiring inmates to show available, feasible alternatives and to produce evidence of substantial risk of severe pain — a demanding standard that has shaped outcomes [4].
4. Scientific, medical and human-rights critiques fueling litigation
Medical journals and experts have testified that extreme hypoxia can produce acute terror, convulsions, and a sensation of suffocation, evidence used by challengers to argue nitrogen causes “conscious terror” and therefore cruel suffering; veterinarians and researchers have also warned nitrogen euthanasia is distressing for many species, which opponents cite to support claims of inhumanity and to press state courts to recognize state constitutional protections beyond federal precedent [4] [5] [10]. International bodies and advocacy groups have labeled nitrogen executions “torture,” amplifying political and legal pressure even where U.S. courts have not uniformly blocked the practice [11] [12].
5. Outcomes, uncertainty, and the role of politics
Outcomes have been mixed: some executions proceeded amid public controversy and witness accounts describing gasping or prolonged deaths that opponents labeled “botched,” while other planned uses were stayed or remain tied up in litigation and evidentiary development; legislators continue to press for statutory fixes or expansions, often along partisan lines and framed as pragmatic responses to execution “desperation,” suggesting the legal landscape will remain fragmented and contested as new factual records accumulate [12] [8] [2]. Scholarly law reviews and commentators argue state constitutions could impose stricter limits than federal courts have, meaning future challenges may find different results depending on forum and the evolving scientific record [10] [4].