Good question! [There may be hope for this one, yet. Pocketing the chalk before she goes into the explanation, complete with hand gestures.] Trials are for when people have done something wrong, and they need to be punished!
It's like a game, where the suspect thinks they have a chance of coming clean, but it's really just a chance to watch them ~squirm~ while they get smacked down with judgement.
[Blissful sigh.] It's almost the best thing, EVER. [Except, of course, the sentences.]