Uh.. actually it wouldn't make sense for the last person to close in these cases. Only permanent employees have keys to the building. The remaining instructor is an adjunct and as such doesn't have access to all the building.
And with all this stuff going on with that strange student - I am VEY glad that building keys aren't given out very easily! Right now I have the security system watching the only unlocked entrance. I know who's coming in... and that they're going to that one class.
The remaining instructor is an adjunct and as such doesn't have access to all the building. Ah...OK. Hadn't thought of that possibility.
I have a key that works in just about every door in the main buildings on campus - all but the residence halls. On the one hand, it's very convenient...on the other hand, if I was ever to lose that key, I could be fined a LOT. Like thousands. 'Cause they'd theoretically have to rekey everything.
I am MOST careful with my key!