You make a quick slight-of-hand in this comment. You start off talking about how gun violence, as a whole, is at low historic levels. Then, you go on to talk specifically about school shootings. As far as I can tell, school shootings are at historically high levels.

It seems legitimate to report on that considering schools are places that parents send their kids every day and have historically viewed them as safe. Add that most schools are publicly-run institutions and you have an interesting story of children shooting children at government run locations. If that doesn’t seem newsworthy to you, the bias may be in your own interpretation.