"He was on serious medications to deal with his issues."
There is no actual medication for "Asperger's syndrome," which is what his brother said he had - because "Asperger's" isn't a real thing. "Asperger's" is allegedly a lack of normal social awareness and behavior - a catch-all just like bipolar disorder, ADD and all the other made up "mental disorders" that psychiatrists have pushed in order to generate an income based on selling pharmaceutical drugs.
There has been no mention in Lanza's case at all of schizophrenia or any real disorder that can cause violence. People unfortunate enough to be labeled with "Asperger's" usually get put on anti-anxiety drugs - which have withdrawal effects that could damn well have caused Lanza to have a psychotic break powerful enough to do what he did. Combine all that with guns and it's no surprise that this keeps happening again and again and again.