For fuck's sake Zod, we are speculating. Dont be such a kill-joy. We can take bets if you prefer.
Noooo. That is not how that shit works. The legal standard for an insanity defense is that you did not know at the time that what you were doing is wrong. This can take the form of a complete psychotic break, OR elaborate delusions.The level of intricacy of his planning of the attack probably rules out an insanity defense even if he is schizophrenic.
You have to remember, schizophrenia is not just hallucinations. You dont hear the voices telling you they are angels and you have to do what they say. You hear those things yes, but the rationality check is also short-circuited. Even if when medicated you know they are not real, you dont know they are not real when off meds, or when the meds become ineffective--which they often do when you are stressed, take cocaine or other dopamine agonists (which will instantly cause an "episode" even in medicated schizophrenics), or when your body simply compensates for the presence of the meds and returns to its default crazy state.
One can engage in some pretty well-thought-out plans under those conditions.