With just cause, many people are struggling with school safety. Obviously, there is no one-size-fits-all solution.
One approach is crime prevention through environmental design, precisely what corporate America does to harden its facilities against attacks. There are many challenges, but the ultimate objective is to deny a shooter access to the facility.
So in the near term, we will need to deploy qualified personnel to stand guard over our children. In the long term, we need to erect barriers with controlled access points. This will require money but will be less costly than posting personnel. Nothing will be absolute, but a security fence may be a viable approach.
Perhaps money requested to build a wall along our southern border could be redirected to assist school leaders to construct fences to help protect our children.