While both participants made good suggestions (the need to "harden" schools against intrusion; hire more security staff; provide more student mental health services) what is equally important is public education. Children aren't born with parenting instructions and the general level of knowledge of child psychological development and developmental psychopathology (a term coined by my doctoral advisor) among the public, teachers, doctors, and the legal system is low.
The basic ego capacities, those governing control of behavior and thinking, modulation of mood, distinguishing reality from fantasy, and developing a sense of who one is (the "sense of self") depend on experiencing a "good-enough" though not perfect parenting. The great power of the unconscious over behavior during childhood and adult life is another critical factor.. Pamphlets and instructional video explaining this, in a supportive non-judgmental fashion, might produce significant benefit at relatively low cost.