In a perfect world, I'd agree - if law officials were to perfectly convict guilty people each time, and if execution methods were absolutely flawless with painless/instant death. However, that's not what happens in the real world.

There's an amazing video by Jacob Geller on execution methods, where he talks about the history and the present of death sentences, but in short, not an insignificant amount of people get falsely convicted and then executed, and the execution methods US are using focus more on "appearing humane" rather than effective/painless, and the incompetence of the executors turning some of those executions into hours of agonizing pain.

For sure, I agree it should be used only in cases where we're absolutely sure that they did it. For example, mass shooters that are taken into custody mid-shooting and there is an absolutely undeniable chain of custody to ensure that the wrong person isn't getting killed.

That doesn't seem possible, at least in my country. The fact that we have executed people that turned out to be incocent later makes my stomach turn.

I don't have a problem with the state killing people in principle. I just have a problem with the state killing the incorrect people (actual, guilty people that don't deserve to live).

Death penalty does not deter crime though, each and every piece of research confirms that

What is your stance on the risks of killing innocent people through failure of the justice system?

Death penalty is final, there are no take backs. One mistake means a life is lost with no possible way to resolve it

Even life in prison, after decades, if fixed means you can give a person back some semblance of relief, especially if the prison system stops being punitive, but rehab based.

The whole point of being in jail, is to learn of your mistakes and not do it again. If you die, you don't learn anything. The others do but that way of someone learning is quite cruel and not fitting in a democracy because fear is undemocratic.