At the end he was tried as mentally unfit, in real life that does not meet he'd get released. The only thing pleading insanity could save him from would be the death penalty. a psych ward is not a place any sane person wants to be in. The whole "pleading insanity gets you off with lighter charges" isn't true. You could even spend more time in the mental ward than you were actually sentenced for. If they found him guilty, insane or not, he would never out of prison ever again.
At the end he was tried as mentally unfit, in real life that does not meet he'd get released. The only thing pleading insanity could save him from would be the death penalty. a psych ward is not a place any sane person wants to be in. The whole "pleading insanity gets you off with lighter charges" isn't true. You could even spend more time in the mental ward than you were actually sentenced for. If they found him guilty, insane or not, he would never out of prison ever again.