This usually means pass more laws, push more regulation, spend more money. Let's get real. We must enforce laws already on the books, and urge mental-health professionals to do their jobs. Let's also keep things in perspective. Crime is down.
Shootings are down, including school shootings.
But, we also must examine why this shooter failed to pick on bigger, more symbolic targets. They armed themselves. They were prepared. The Bible, the Torah, and the Talmud make numerous references to the importance of preparedness and self-defense. We must remain vigilant, acutely aware that bad guys exist.