Amendments don't apply when you fuck with The Oligarchy ~(TM)~

Most lawyers advise against invoking that. Gives all sides more time to prepare. Like the defense spent a good bit of time trying to get certain evidence removed from the record as it's own proceeding. The hope was of course if the judge found that the evidence must be excluded then the prosecution may drop charges even before the trial.

So yeah Luigi could have had a trial, but I can almost guarantee his lawyer is slowing things down to build his defense and try other types of hearings that strengthen their position once a trial begins

It's typical in cases like this to waive your right to a speedy trial.