Perversion of the justice system-R-US

From Fox:

Lashing out at the judge and the lawyers appointed to represent him, Zacarias Moussaoui said he is being set up for conviction as a Sept.11 conspirator by the very people duty-bound to protect his rights, according to court papers released Thursday.

Why is this guy even on trial? Why wasn’t he immediately handed over to the military for some serious grilling, and then left staked out in the high desert?
(Hmm…unintended bit of punnery, there…or would he bake in the desert rather than grill?)