I've always had a problem with people using an "insanity" or "not criminally responsible" argument in court. If the evidence is clear that person X killed person Y, then person X should be locked up or otherwise punished appropriately. If they're successful at using the insanity defense they usually end up spending a few months or years in hospital or a psychiatric institution before being released back into society.
This shouldn't be happening.
The real problem is the sentencing. Lunatics should never be released. They should stay in a suitable facility until they die. In fact MORE murderers should be classified as insane because only an insane person could willingly kill another human being. This would end the notion that a life sentence is twenty-five years. Let's just remove these people from society forever, and let them work during their sentences to pay their way for cost of keeping them behind bars.
And no more plea deals like that woman I won't name who, after killing her own sister and two other girls, made a deal that sent her ex-husband to prison for life while she walked free after only ten years.
I know people who say, "They're of no benefit to society, so drop them naked in the middle of Antarctica in the dead of winter." But it's too easy to speak out from the comfort of our own lives and judge these people based on the depictions from the media.