Details: Russell Bucklew, a convicted murderer sentenced to death 22 years ago, argued that a rare medical condition he has would make lethal injection extremely painful, per the Washington Post. Justice Neil Gorsuch wrote that Bucklew failed to propose an alternative method of capital punishment that would be less painful, arguing that it shouldn't be a difficult task unless the inmate is simply seeking to delay his execution.
I thought Bucklew proposed nitrogen suffocation.
He originally proposed "death by lethal gas." The district court instructed him to clarify. He proposed nitrogen. Nitrogen had never been used for an execution by any state in the US. He was afforded "extensive discovery" to find an expert to support the assertion nitrogen could be used in an execution. He found none. Thus, without any expert, without any medical documentation in support, and without any evidence, the court found his proposal "lacking."
There are methods that are probably painless. Putting them under general anesthesia is probably a good way to start.
I don't think we should be doing it at all though, for a few reasons. A big one is there are innocent people on death row. We know this because it is proven on a fairly regular basis. Sometimes people end up on there because of prosecutorial misconduct, coerced confessions, planted evidence, pseudoscience from crime labs etc. The list goes on. The way the system is set up means we have killed and will continue to kill innocent people. That is simply not something our country should be doing.
Without debating the merits of the capital punishment, I agree that there should be a completely painless method and I struggle to figure out why it is so difficult to do. I know nothing about medicine, so, pardon my ignorance, but, like you, I never really figured out why they are not put under general anesthesia first. I have (unfortunately) had to put down a few beloved pets and the process at the vet certainly seems very peaceful. The beloved pet is completely asleep before the fatal injection is given. It is rare to see so much as a muscle twitch. Yes, I know, canine vs. human, but, it shouldn't be that different.
That's actually pretty easy to answer. A completely painless method does not satisfy the quest for vengeance. The only real supporters of the death penalty any more are those who seek retribution. A peaceful passing does not give that in their eyes. Just read some of the early responses to this thread.
We are so fucked.