The Stella awards!!! you gotta read this.

[Andromeda18_]

I just wish every person who was let back into society and kills again would go after people with these kinds of opinions. If someone in your close family was killed by someone who was let out because they're supposedly better now I doubt you'd still have that same opinion.

It might surprise you but I don't exactly disagree with you. By saying this I don't mean I agree that mentally unstable people should be killed or even put in prison but I do believe they're not properly taken care of. Another flaw of the system, and not just the American one.
For one, more often than not they aren't treated the way they should and even if they are there's always the risk that once they're released they'll commit a crime again for one reason or another. There isn't, at the moment, an appropriate way of dealing with mentally unstable people who have commited crimes and that's the real problem. Maybe they should never leave the mental institutions they're put in, or maybe they should only have a controlled freedom. What I know is that a person who's commited a crime due to disease shouldn't be treated like someone who commited a crime out of her/his own free will.