Though I think this article is very interesting and insightful, the author made a lot of disorganized points.

An FBI study on school shooters found school shootings are never a result of a crazy person “snapping.” Most shooters do have serious mental health or emotional issues, but they all plan their attacks months or even years in advance.

If "snapping" from mental illness is considered a moot reason for the shootings, then why does the author encourage the reader to show empathy for those who are psychologically unstable?

They are distractions from what is right in front of you and me and the victims of tomorrow’s shooting: people who need help. [...] there’s likely another young man out there, maybe suicidally depressed, maybe paranoid and delusional, maybe a psychopath, and he’s researching guns and bombs and mapping out schools and recording videos and thinking every day about the anger and hate he feels for this world.

Mental instability seems to be the root of the problem according to this paragraph, but again the author cites this FBI study that is contradictory to that idea.