Being a "librul" and all, people almost get offended when I say I do support the death penalty. When you learn that everything in life is impermanent and not to get attached to things, your mind kind of wanders into the area of "you shouldn't get too attached to life either"; it comes and goes, the world keeps turning. No big deal.
Now, who it's used against, is my only contention. There is just plain evil out there. You know it when you see/hear/read about it; the guy in that tower in Texas, the North Hollywood Shootout suspects, the DC Sniper, Charles Manson. Jeffrey Dahmer. Whether it's a mental break, insanity or whatever, once they willingly kill a person their lives all become forfeit as far as I'm concerned. Read Truman Capote's "In Cold Blood" if you want a detailed look at a couple deserving candidates for the death penalty.
People like that who have shown a complete disregard for life don't deserve to continue living.