It’s hard to understand the level of inhumanity needed to go on a school campus and start shooting people. But it’s also hard to fathom why someone would seek to prey on the heightened fears that exist every time — far too many times — a school shooting does occur. But they do, and it happens. And this past week it happened at both Analy and Santa Rosa high schools where someone left threatening messages on the walls. Piner High School also had a scare when a neighbor reported a suspicious person carrying a dark object — an object that turned out to be an umbrella. Those found responsible for these threatening messages should face serious consequences. Calling these actions a sick joke is an understatement. But we give a thumbs up to a number of teachers who made these episodes teachable moments — at least for those students who came to school. Among them was Santa Rosa High history teacher Andy Brennan who used class time to talk with students about what they need to do if an active shooter arrives on campus. It’s sad that it has come to this. We don’t believe the answer is to arm teachers or administrators. But until lawmakers get serious about keeping weapons out of the hands of unstable people, arming students with the right information about how to flee or fight an armed intruder will need to be part of the regular school curriculum.