I approve of the death penalty for serious crimes when there is minimal doubt of guilt. For instance if the accused confesses. I would recommend the guillotine. It's cheap, simple, there's very little that can go wrong, it's instant and painless (I know people think maybe the head is conscious for a few seconds but this has not been proven and I would accept the risk), and there's no ambiguity about whether the person is dead or how long do we have to wait. You could have five strings attached to it, only one of which really triggers the blade if you want, the same principle as a firing squad.
There is no scientific evidence on using nitrogen to execute people.
eji.org
There is no scientific evidence on using nitrogen to execute people but it is generally not used to euthanise animals because it causes panic and distress.
Risks include feelings of suffocation and choking to death on one’s own vomit, as well as brain damage, a stroke, or a persistent vegetative state instead of death.
Exposure to less than 100% pure nitrogen gas can cause severe and permanent injuries short of death, according to experts.
Alabama’s protocol calls for delivering nitrogen gas to the condemned person through a mask, which experts say creates a substantial risk that oxygen will infiltrate the mask, which could leave the person in a persistent vegetative state, cause him to have a stroke, or to experience the painful sensation of suffocation. [Witnesses to the execution reported the mask was not airtight, which could be why Smith thrashed around for several minutes if he was slowly suffocating while conscious.]
Vomiting is also a known side effect of oxygen deprivation. Using a mask that covers the nose and mouth creates a risk that the person will asphyxiate on his own vomit, especially where, as here, prison staff will not intervene to check or clear the person’s airway if he vomits after nitrogen has begun to flow.
The American Veterinary Medical Association has declared that nitrogen gas is inappropriate for euthanising most animals. Its guidelines provide, 'Current evidence indicates this method is unacceptable because animals may experience distressing side effects before loss of consciousness.'
'Veterinarians have generally stopped using nitrogen to euthanise animals, who showed severe signs of distress,' The New York Times reports.
