Cruz was an individual diagnosed with autism and depression at a young age; she was most likely referring to the eccentricities that come from those conditions.

He only began showing violent tendencies in 2016 when he cut his arm open with a sharpener (the teachers and Deputy Peterson [the same one that was there on the day of the shooting] put it in his report but they never sent him to a mental hospital for some reason [despite it being recommended, being in Peterson's power to do so, and Cruz wouldn't have been able to get a gun, or at least would have had a lot of difficulty]).

But even if he was initially violent I don't think it justifies having him bullied since middle school.

Going after guns is the far more simple and immediate solution than dealing with human behavior.