"Just because somebody committed a crime once, doesn't mean he will do so again. And keeping criminals forever locked away is not the reason prisons exist."
Well, I'm not saying anyone specific should be locked away for life nor am I arguing people can't be rehabilitated. What I am stating is that the act should be judged by the act alone - rehabilitation comes afterward, and not necessarily to everyone. They are two separate components of the consequence of committing a crime. If a man murders another with clear intent, then this should come with x amount of years as sentence. I do not believe one man should get less years than the next because the former was driven by tragedy while the second was driven by some sadistic joy he gets in murdering - a murder is a murder.
I agree you should not keep anyone under the assumption he might commit another crime but saying "following your logic, no criminal should ever be able to get out of prison" -- is simply false, because what I'm stating is that the punishment be dealt in an objective manner, whether this ends up being 3 years or life. Clearly, if the man was rightfully sentenced 3 years, then he would be out in 3 years - I fail to see how he'd remain locked up for life.
Prisons must punish and rehabilitate. I believe the x amount of years is the punishment, whereas rehabilitation is what follows to help the convicted once he's been rightfully punished. To claim a treacherous act does not merit a punishment is absurd - I really don't even know how to argue that. Prison isn't meant to be some happy rehab center where people go in to repent and start fresh - imprisonment is a form of punishment. To summarize, I never stated anyone should be locked away for life because they might all commit further crimes - I stated that his emotional status should not affect the sentence that his dealt to him.
"What happens if another tragedy happens to him" I think it's important to note I put this forth not to argue this man should therefore be locked for life but to address that like it or not, a crime begets a punishment. And as such, garnering sympathy has no place in law because it makes the judgment subjective. People are using the tragedy to justify his intent of murder but that is just downright barbaric. If he rehabilitates, so be it - release him sooner. But the very initial punishment that he is sentenced should not reflect the sympathies of those around him. Then all you're saying is that some people simply deserve to have their vengeance carried out and murder - and that's an incredibly subjective line to draw. Or, that's just my two cents I guess.