A counselor then? Sounds more like someone you'd go see than a class, like you mentioned Zeth. 
Could be someone that participates in de-breif (after action review) after missions are completed, or mock missions in the case of students. Though I'm sure with a school full of killers the occasional student will need a psych eval to measure how useful they'd be and their mental stability throughout the RP, just for realism.

I think the character would be useful, though I can't imagine you using them very often.