Consider the alternatives:
1. Lock the guy up for LIFE, at great expense to the taxpayers.
2. Try to cure his mental illness, again at great expense to the taxpayers. Upon being "cured", everyone gets to worry about whether it will happen again. (I do not believe in "temporary" insanity... if you go insane once, what's to stop it happening again? Once insane, ALWAYS insane in my book.)
In the meantime, where's the justice for the families of those killed by this guy's actions? He killed their loved ones; they should at least get to see him die at the hands of the state. He doesn't have a leg to stand on... it's obvious what happened, so there should be no question, no lengthy appeals process, etc.
I'm not trying to convince you to be pro-death penalty... just explaining the logic in support of it. (In other words, this is all I have to say about it.

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