To early to tell what and when things happened. I will wait and then evaluate. To many unknowns, other then the body count which is terrible. I do know that in those instances if they have had active shooter training and employ those tactics we are always behind the curve. That has to be the worst event to have work through. I feel for those people involved, parents, police, teachers and staff. Terrible.
It sounds like schools need to be hardened.
One entrance/exit where on duty cop monitors anyone.
Another entry/exit? Another armed cop.
Armed teachers and qualified volunteers like retire pole and military would help.
Standardization of these practices with every school. Don't "Leave it up to the school district"...
If they can spend tens of millions of dollars on new school buildings, stadiums, etc, they can afford to protect the kids who go there.
