The
writer does not distinguish between "open" and "unlocked" well enough to know about the status of other two building doors. [I'm not sure of the relevance of the status of those doors unless they are part of the crime. Also, we are not told where are they located].
Does
open mean standing open/ajar to any degree? Or does
open mean unlocked?
Also, we need to know whether the door he went in had a handle. If it was closed completely shut with no external handle, how could he open it even if unlocked?
Also, any teacher who does not know whether there is an SRO assigned to her campus/building and how to reach that officer is not well trained/prepared for an emergency.
There is still lack of clarity. So many questions!
JMO