A thought just occured to me. What if they were thinking of the condo as a firing position since the school was across the street.
How hard would it be to take over the average apt bldg in an average place? Not very, I would imagine.
Quite so, sadly!
I would encourage folks in such buildings to find out who is conservative and has guns and who doesn't. Make sure one has their cell phone numbers programmed in ahead of time AS WELL AS MEMORIZED.
Perhaps a phone tree if several families have guns. Double up one exposure on the phone tree for those unavailable.
Also, Explore setting up private network/LAN webcams for those conservative, healthily paranoid types to help keep watch on the building.