We are hearing about how fault finding is going on with the school.
I think a reasonable solution to the school shooting events of the last decade or so would be prevention. How can it be prevented?
First, all schools should have a "zero tolerance" policy on bullying. By this I mean, no verbal abuse or gestures are allowed. I expect most physical violence between students is preceded first by verbal abuse or unwelcome comments, sentiments expressed by gestures, strange clothing etc. This would include written comments etc on school property or books covers etc.
Second, all schools should have a respectful school policy. For example, a dress code guideline to prevent some students from expressing their rebellion against others through extreme cloths such as long black trench codes. School uniforms are not necessary just general guidelines, with a provision for special case decisions as creative students try to get around the rules. Just tell them they can dress any way they like when they are out of school. Anything that can be interpreted as being disrespectful towards fellow students or teachers must not be tolerated.
Third, extreme cases should be reported to the police. That's their job.
The parents should be asked to vote on these rules to gain their support so it is not "just the school authority".