Asklemmy

I don't know. On one hand, if the crime is so bad that it otherwise warrants lifetime imprisonment...

a) maybe there is a line past which it's deserved. I do generally view life as being something sacred and not something you should be able to take from others, but it's a fuzzy moral question as to whether there are some acts that are so heinous that they would challenge that view. Maybe it has to be for a harm at a societal rather than personal level? Like maybe taking one person's life isn't a warranted punishment for them taking a single other life, but perhaps say, a Nazi has harmed not just so many people, but some essential essence of the society that keeps us happy and healthy. Maybe THAT is bad enough to merit the ultimate violation of personal rights?

b) Is the alternative THAT much better? Is condemning someone to spend the rest of their life in a tiny room with no hope of them ever getting to do something that they want much better than death? Is it really living a life? (Granted, my opinion on that point is colored by my depression. I genuinely think if things got bad enough in my life suicide would be a preferable alternative. A healthier person might have a different view.)

That said, regardless of the above considerations, there is also the issue of the permanence of the punishment not allowing for correcting mistakes. Humans aren't infallible. Plenty of people have been wrongly convicted. If they're merely put in prison then we can always free them if we later learn of our mistake. If we've already killed them... ooops...? Nothing we can do. So perhaps that issue overrides any other moral considerations.