Honestly, I beleive if someone has done something to warrant the possibility of the death penalty, they should rot in jail in solitary confinement... They clearly don't value the lives of others, so why should they be given the option to socialize and live a decent life? I get that these people often have drug/mental issues, but I've watched enough of The First 48 to know that 95% of the murderers out there only show the slightest bit of emotion when they realize they've been caught... and it's selfish emotion, knowing they're about to rot in jail, not that they just murdered an innocent person. I don't think they deserve to die, either, because that's almost like an escape for them... I personally think death is an easier alternative to living the rest of your life in jail. I think they deserve to suffer.
Of course, that only applies to cold blooded, horrible people... Not someone who shot and accidentally killed the person who was trying to rob them. I do hate paying for these people to live in jail with my tax money, but I think many prisons spend much more money than need be to "improve" the living conditions for inmates... So that is BS imo. But, if every murderer knew they would be humanely killed (not like they're going to get the electric chair anymore..) soon after committing a crime, I think that would give them even less incentive to think before they act.
Sorry if that makes no sense... I'm really stoned lol.