100% for. But not in terms of revenge.
Here's the problem we have: There are some people who demonstrate themselves to be incompatible with free society. They've shown that they are capable of inflicting traumatic, indescribable levels of pain on others.
The debt they take out against society through their crimes is something they simply cannot ever repay, either.
With people like this, rehabilitation isn't an option. When you have a person like, say, John Wayne Gacy...a person who has brutally murdered children for no greater purpose than self-satisfaction...even if you *could* rehabilitate the guy, the only way you could test your success would be to release him into a situation where he is able to murder more children. If he doesn't murder any, great! You rehabilitated him! If he does...well, the cost of your failure is one or more young boys being murdered in a most catastrophically torturous manner.
Simply put, the bet isn't worth the hand.
Our options are limited to two things, then: We can lock the people like this in a concrete box and wait for mother nature to do our dirty work, or we can go ahead and give them a quick and painless exit from a life they simply are not equipped to handle.
I don't want to torture people like Gacy. Forget what he "deserves", because they certainly don't deserve quick-and-painless given the amount of pain they've caused, but that's not something a dispassionate justice system can accomplish. Most people don't get what they deserve...for better or worse. His victims didn't get the death they deserved, and killers like him don't get the death they deserve either. But I still think it's irresponsible to bring bloodlust and vengeance into this, even if we are 100% sure of guilt.
I think the most practical solution here for all of society is to put people like this in a sealed chamber and fill it with an inert gas like argon or nitrogen and let them drift off into unconsciousness in peace.
In a system where guilt is assured, I'd take up a job as executioner of such people and I'd never lose a minute of sleep over it.
I'd be "pro choice". I don't think, we should murder anyone, for any reason. But if the perp himself chooses death over a long/life sentence, I'd grant them their wish.
Damn. That’s a good question. Honestly, I would be really picky about the crimes, but I’d say for. Stuff like repeated child molestation or pedophilia. And only when rehabilitation has failed. When someone clearly has no interest in helping themselves and only cares about hurting others.