I strongly believe everyone deserves a fair trial. That said.... in my fantasy court room, it would go like this.
Judge: Ok, opening statement from the Defense
Did your client shoot up and kill a bunch of people?
Defense Liar (Lawyer): Our client is a poor misunderstood boy, he needs extra special treatment and love. He didn't mean to hurt all those people.
Judge: wait a second, he willing shot everyone there, right?
Defense Liar (Lawyer): well yes, but he's insane. He needs a glass of warm milk and a hug from his moma, not the chair.
Judge: but he pulled the trigger, right?
Defense Liar (Lawyer): well, uhh, yes, but don't you know he just forgot to take his special pills that morning. As long he takes his special pills, everything's peachy.
Judge gives the Defense Liar (Lawyer) a
look: ok Mr Prosecutor, your opening statement.
Prosecution Liar (Lawyer): The state has nothing further to add.
Judge: well I see the jury has already begun throwing a rope around the tree in the front, I think its safe to say they've reached a verdict.
Seriously, the fuck nut's own lawyers admit he did it. This trial should take a fucking day (even allowing for a nice long 2 hour lunch for the jury), a week for an appeals court to verify it was a fair trial, and another week at max to hang the cocksucker in public.