Using that mentality, one could say the government doesn't have the right to imprison people at all because individual citizens don't have the right to imprison people.
That's like comparing apples and oranges, my friend. No one is disputing that people like James Holmes need to be locked up FAR away from regular society.
I agree that life imprisonment works if it truly means spending the rest of one's life in prison. If a jury can prove beyond reasonable doubt that a person committed a crime heinous enough to warrant such a sentence, then lock them up and throw away the key. I'm with you on that.
My issue (and therefore my "mentality", as you call it) lies solely with capital punishment, and you can try to twist it any way you see fit, but the bottom line is this: there is something immoral and hypocritical about punishing someone with death for killing another person.
