People murder for different reasons, whether its hate, passion, or due to a mental condition. Their motivation shouldn't matter though when considering the punishment.
What I say is not "bleeding heart". Its pointing out the hypocrisy. Think about it:
"He killed a man! How awful! So lets kill him back to prove that killing is wrong!"
See how ridiculous that is? All killing does it beget more violence, and more violence seeps into our society. Lets deal with things WITHOUT violence, and maybe, just maybe we can prove that we can deal with things in America without knocking heads off and leave them to roll about on our flawed court system floors.