Also, the security officer could (probably not) have special deputy status with the county. She would have full LE powers while on duty as security. Did she have a gun?
No gun, taser, cuffs, or anything. Just a radio and an ID badge.
So if they have jurisdiction off campus, how does that let them enforce a law that, to my knowledge, doesn't exist?
I don't believe it's illegal to carry on campus (am I wrong?) - just against the rules. But how do those rules apply as enforceable law off campus?
Exactly.