I agree. I don't understand the people who say that killing a murderer makes you as bad as the murderer. No it doesn't. What makes the murderer so bad is that they kill innocent people for their own sick pleasure or selfish gain. Killing a murderer so that they have no chance of murdering anybody in the future is not even close to the same thing. It's a form of justice. We legally recognize that, which is why the death penalty exists in many countries.

I don't think that torturing people is right under any circumstance though, because that's not about preventing future murders or protecting society anymore. That's about bloody revenge.