My age makes my memory span a long time.
When I was a kid, there was very little of this happening...OR if it did happen, there was not a news media to pound every waking moment of the "event".
I have NO DOUBT about the fact that there are others who turn on the TV, and listen to the news who figure...."someday I will do that and more...."
I have NO DOUBT that there are sick members of society who want to "get off...." but only know that THIS IS THE BEST WAY TO DO IT!
I have NO DOUBT that this event will have HUGE over-reactions...anti-gun....armed school guards.....tons of legislation...and arm chair generals who will use this as a means to get some political footing on something.
I have NO DOUBT that the press will dutifully interview the NEXT mass murderer's friends, co-workers, and ex-teachers who will dutifully specify that " ....always thought this guy was a nut job...but didn't think he would do this....."
There will be a huge over reaction to a troubled society that WE have created one way or the other....and that lurking in some parking lot, apartment building, family friendly subdivision is another sick person who can easily top this one; to which we will dutifully report on for hours and days....and hone up yet another would be mass murderer who will get his 15 minutes of fame.
It is a self propagating prophecy
As a society we feel we are "above" previous societies who used to stone and hang those who had deviate behaviors. These are the prices of those foolish ideals. We counsel them...explain why this is wrong and let them go, satisfied that they are now reformed...for the moment.