The way it is practiced in the US is both inefficient, incompetent, often unjust (racism, poor legal representation, biased judges/juries, evidence tampering, unreliable witnesses, dna evidence, etc), often controversial, needlessly cruel, and obviously not working in terms of its supposed preventive function. It's a mess.
That's the reason why an increasing number of states are opting not to. It's just too controversial of a topic and the political price of getting it wrong is too high. It's a PR nightmare and it's one of those things that is only getting harder because of all the recent problems failing to get it right. At this point all executions are highly political and typically only pursued in states where this is relatively uncontroversial. All opponents have to do is point all of the above out. Which of course they do.
The hypocrisy around trying to humanize what is basically state sanctioned murder has resulted in weird practices around multiple executioners pushing a button to avoid knowing for sure whether or not you killed the person, weird rituals around selecting the means to kill where the result is neither humane, particularly efficient, or cheap. The whole thing is a weird guilt trip gone wrong. Ironically this has made it more controversial, not less.
From what I understand, killing people swiftly and painlessly is not technically hard. Any vet or butcher knows how to put down an animal humanely. This is done routinely every day. E.g. a bit of N2, N2O, CO, or similar is all you need for what is pretty guaranteed fatal and painless. Hypoxia followed by unconsciousness in seconds and death in minutes, typically. The main objection against this particular method seems to be that it is too humane (make up your mind already). The key point of that is that the death penalty is primarily about revenge and not about prevention. Stating this further de legitimizes the death penalty and is in itself controversial. State sanctioned torture is even more controversial than the state sanctioned executions.
At least the Brits were efficient and competent about hanging people. It's the systemic incompetence around the death penalty that is killing it in the US. Either way, I'd suggest fixing that level of incompetence and getting that off the table at least. I'd say the Brits were wise to get away from that.
You can't give a person two decades of their life back either.
Sure, it's better to only take away two decades from someone than all of their remaining years but not as much as people like to believe. Especially when you consider that earlier years have a much higher utility than later years. And later years have again higher utility if you could freely spend your earlier years creating a life you would enjoy, in particular have kids to watch them grow up.
The rate of suicide is much higher in prison than out, and is also higher after release for people who have served their prison sentence.
And that's without an impending death sentence - just a regular prison term.
I can't imagine it'd be that different because they were incarcerated incorrectly.
Here's a list, for example: https://deathpenaltyinfo.org/innocence-cases
edit: and why would you expect differently about suicide rates? Prison is awful. It is punishment, and it the punishment doesn't end after you have left because loss of vote, inability to work in many fields, social stigma, and broken relationships. However, generally speaking, most people in prison are guilty (even if many are not). It is a distinctly different group than people than those exonerated after a death sentence, who are invariably not guilty and they know it. The two groups aren't comparable even though one is a subset of the other.
I’m sure you’d change your mind.
You also can't un-imprison someone. Sure, you can release him, but he'll never get those years back; his relationships will never be the same again; the trauma of imprisonment will never leave him.
I think the thing which needs to be done is to fix the judicial system: if we can't rely on it to correctly impose death, then we can't rely on it to correctly impose imprisonment. Maybe we need to incentivise prosecutors differently; maybe we need to conduct investigations differently; maybe we need to adjust the jury system.
Some people are against capital punishment in any case even if it is 100% painless and the judicial process is completely correct. I don't really have anything to say to them: it's obvious to me that there are certain crimes which absolutely merit that punishment and that to refrain from killing the guilty in that case is a profound injustice.
Well, a good thing is to not immediately cut off any possibility of reaching a common ground.
I think you describe the issue perfectly. Given an imperfect criminal justice system, how to you administer punishments?
Maybe the DA, the police involved, the judge, and every member of the jury should all be summarily executed in the case of wrongful conviction involving the death penalty? I can see some crimes that merit the death penalty, and if everyone involved had to risk their own life to apply it I would be more comfortable that it was not applied lightly because of racial/socioeconomic issues, police misconduct, or the political ambitions of a district attorney.
That's only the case if you believe in free will ideology. The injustice is "society" villainizing a person who had no control over their fate if you understand free will is an illusion because of determinism and how the brain functions.
Free will doesn't exist in society and similar to humans. The will of society is a summation of all the preceding forces upon generations and without any real control. The result being what we experience today as our society we live in.
This all is important to understand because hidden in it is the knowledge of why we have what we have now. Also the fact of how important the majority operates, behaves and thinks.
Currently, the majority thinks contrary to the fundamental truth of how their life will play out. I hypothesis if this wasn't the case, our society would adapt and because there is something similar to moral judgement.
Basically, the collective unconscious of society. The objective is made with effort of being positive, fair and right. That's assumed with how the majority believes the justice system we experience today is right and without understanding the true knowledge making it neither positive, fair or right.
The incorrect perspectives of how reality is,.. collectively prevents evolution of society and because the collective unconscious is still fixed upon incorrect beliefs. Thus, I think I'm sort of answering your question.
Part of it is the incredible disparity between the equitable application and quality of defense based on class and race. Seems like you have to fix the criminal justice system before you make an ultimate and irreversible punishment more efficient.