I like this approach for a start of confronting this problem. I work in the medical field and we have had restricted entrances for many years now where we have armed guards posted. We also have procedures for active shooter in place. Do I like this? Yes and no but the reality is that this is our world. Someone who wants to hurt people will find away regardless of laws. Schools should have a variety of precautions to choose that fit their particular circumstances. I hate it when every answer is ban this or that as if evil people or "troubled" person will allow that to stop them.