>On the brightside(?) with all his autistic ramblings at least he has an insanity defense.
Insanity defense almost always fails. From what I understand being a nutcase is not enough to be declared legally insane. Rather, you need convince the jury that you're mental state prevented you from knowing your acts were illegal in order to mount a successful insanity defense.
I find it more likely though that he would go pro se, he's narcissistic and delusional enough to do that. Read up on trial of Colin Ferguson, I think that the S4T trial will be a remake of it:
https://en.wikipedia.org/wiki/1993_Long_Island_Rail_Road_shooting#Trial