Before Alabama put Kenneth Smith to death by nitrogen suffocation on January 25, state prosecutors assured the courts that he would be unconscious in seconds on his way to a peaceful passing. It was the same false promise execution proponents had previously made when states introduced the electric chair and lethal injection as new and improved humane methods of execution.
Instead, eyewitnesses — including family members of Elizabeth Sennett, whom Smith was convicted of killing — reported that Mr. Smith “convulsed,” “writhed,” and “shook” “violently” for more than two minutes after being administered the lethal gas and, struggling against the restraints that bound him to the gurney, “gasped” with his chest “heaving” for at least five more minutes before his breathing slowed and he lost consciousness about nine minutes into a 22-minute execution.
Alabama officials said they saw “nothing out of the ordinary” or unexpected in the way Mr. Smith died, and state attorney general Steve Marshall described the execution as “textbook.” They most likely are right — but not in the way they want others to believe. The torturous display every independent observer reported about the Smith execution is what we can routinely expect to see in nitrogen gas executions.
Death penalty proponents call the process nitrogen hypoxia, a euphemism that obscures the reality of asphyxiating a person to death by pumping their lungs with a poisonous gas until they suffocate to death. Nitrogen suffocation is not the swift, painless execution its proponents claim it will be. It is brutal and inhumane, so much so that veterinarians reject its use to euthanize animals.
Twenty-nine states have prohibited “nitrogen hypoxia” to euthanize cats and dogs. According to the 2013 and 2022 updated American Veterinary Medical Association Guidelines for the Euthanasia of Animals, nitrogen gas “is acceptable with conditions for euthanasia of chickens and turkeys … [and] pigs” but “is unacceptable for other mammals.”1 “Administration of [nitrogen] is only acceptable in anesthetized mammals.”2
The Humane Society of the United States has called the use of gas in animal euthanasia “cruel and archaic.”3 Animals euthanized by gas “might remain conscious for several minutes,” the Society says, “trying desperately to find a way out [of the euthanasia chamber]. They sometimes convulse before losing consciousness, and death can be especially slow to come for animals who are very young, very old or sick.” As of March 2023, only two states — Missouri and Wyoming — still permitted the practice.
The experience with animals tells us that prisoners executed by nitrogen suffocation will likely be conscious for minutes while they experience convulsions and oxygen starvation. The veterinary doctors say that, in gas euthanasia, “Loss of consciousness will be preceded by open-mouth breathing and hyperpnea,4 which may be distressing for nonavian species. … Exposure times > 7 minutes are needed to ensure killing of pigs.”5 The process would be longer for mammals the size of humans.
Kenneth Smith’s execution offers a textbook example of these phenomenon. He was not unconscious in seconds. He was conscious and in distress, experiencing convulsions and exhibiting signs of hyperpnea for a reported nine minutes. His exposure to gas in the 22-minute execution was longer than the seven minutes necessary to ensure the gas suffocation of a pig.
Blind to reality or immune to human decency, Alabama intends a repeat performance on September 26 when it seeks to execute Alan Miller. And in legislative hearings in Columbus on May 21, see-no-evil execution proponents in Ohio will be championing including gas asphyxiation as part of the state’s execution repertoire.
Miller is 59 years old and weighs 350 pounds. The same medical conditions that contributed to a prior botched attempt by Alabama to execute him by lethal injection risk a gas execution that is especially prolonged.
But even without medical complications, gas suffocation executions suffer from an inherent problem that is so simple, it’s “textbook.” The practice is unfit for a dog … and unfit for killing prisoners.
- 2020 AVMA Guidelines at 28; AVMA Guidelines for the Euthanasia of Animals at 24 (2013 ed.) (2013 AVMA Guidelines). ↩︎
- 2020 AVMA Guidelines at 61; 2013 AVMA Guidelines at 49. ↩︎
- Kitty Block, President and CEO of The Humane Society of the United States, In major win, Utah bans the use of gas chambers in animal shelters, The Humane Society of the United States (March 24, 2023). ↩︎
- “Hyperpnea” is characterized by taking deeper breaths than usual in an effort to increase the amount of air taken into the lungs. ↩︎
- 2020 AVMA Guidelines at 28; 2013 AVMA Guidelines at 24. Eyewitnesses to Mr. Smith’s execution observed convulsions and gasping/heavy attempts at breathing for a combined period of nine minutes preceding loss of consciousness. ↩︎