Gun violence at schools started before that (there was Charles...Whitman or whomever in the clock tower in like the 60s or 70s, there was some girl that shot the school across from her house in the 80s, and I'm pretty sure there were others). Hell there was some ratfuck that blew up a school in like the fucking 1920s.
Isn't it weird how many of them involve angry white men that don't even understand their rage but still decide the best way to deal with it is to murder people?
Then again, I could agree with the argument that Jesus isn't taught in schools, especially religious schools where instead they're being taught to worship politicians and hate people for race/gender/sexual orientation/etc and other crap that Jesus in the bible explicitly does not support.