Unfortunately, this is true.
Anyone that wants to run roughshod over a school can simply walk in and start shooting....and there is nothing that can stop them.
I'm definitely not for guns in school....but a "no weapons allowed" sign really is the dumbest "defense" system ever enacted
Each public elementary school has 1000+ children.
A single cop near the front and/or roaming near the front will stop most shootings very early on.
A decent buzz-in system will keep most shooting to the office, where cop is and where adults only usually.
You build schools together, so most elem and middle schools are adjoined. Great for sharing resources/infrastructure AND having the second cop responding fast as well.
Think about it - ANY time in 'real life' you have 1000+ people in one area - you have security guards. The mall has a few guards. Concerts. Even WALMART has a half-dozen security people (Primaily for loss prevention, but armed to some degree at times).
So yes, with each school always having a few people with clipboards that 'look busy' most of the day, and projector systems wroth 40k$ in most classrooms, the $ is there (if they choose) to add a single cop to each school.
Can yall name ANY 'soft target' where 1000+ people assemble that they don't have security? MAYBE church - but at least in FL, many in church are elderly vets who are dang sure carrying anyway.