It's called the Fallacy of Misleading Vividness. While we HEAR about it more (with news at the speed of internet), it's not necessarily happening more. It just SEEMS like there's more now. If you asked almost anyone out there, "Is violent crime / murder up or down?" Most would say, "UP!" They'd be wrong, of course. Violent crime and murder are both down about 50% since 1993 (if memory serves).If memory serves me correctly, the first school shooting was in the 40s, with six dead. Albeit all adults, I believe. I also remember seeing there were more shootings in the 90s than today.
I agree with you on the news thing. We're more connected than ever now. 24-hour news cycle, phone alerts, emails, and the list goes on.