I know that my opinion will not be a popular one, but I think that taking God out of our schools, country, and lives has a lot to do with it. Also, we, as a country have embraced the victim mentality instead of personal responsibility ( both the responsibility of the parents and the children).
I grew up in the 60's and 70's and I went to school with the same 90 kids from K-12.
There were some crazy guys, one who lived across the street from me. He had ADHD, for sure, but no accommodations or excuses were made for him. He was expected to do well in school and expected to behave, neither of which he did very well. BUT there were consequences for his actions and for his poor school work.
He is highly successful today, and he will tell you that it was that little bit of fear of God, his father, teachers, and law enforcement that kept him from going too far.
He had access to guns and was a druggie and broke into homes for a while. He was picked on in school, but often times that was because he picked on a girl (me) and another random guy would step in and punch him. I actually got called to the principal's office one time because he was punching me which led to him being punched several times. He tried to tell the principal that I caused him to be beat up. Principal wasn't having any of that nonsense. He never bothered me again.
I don't know that personal responsibility and accountability is the complete answer, ( as I said, I believe we need God), but it sure cannot hurt. No one is ever happy when they think they are a victim and wronged somehow. That line of thinking brings anger and rage with it.
JMO