[mewzilla]

I'd like to know why the door to that room was locked...

[ValerieUSA]

Teachers often bring their own possessions to the classroom to use as teaching aids and decor. It is reasonable to allow them to lock the rooms after hours - especially if the building's main doors are left unlocked.
It is also reasonable for the custodian to allow a police officer or even a parent into the room after hours upon request.

[Quick1]

I'd like to know why the door to that room was locked... Maybe so kids wouldn't be able to sneak in the maintainence door like the cop did, and walk in the room to change their grades or some other mischief? THINK, people.