For example,in regards to Seung-Hui Cho who killed 32 at Virginia Tech. Many came forward to tell how they had been disturbed by his isolation and anger prior to the massacre. What's the schools responsibility?
Behavior outside the school is tricky because a person is entitled to privacy just like everyone else. But if a person is so mentally disturbed, this should have become apparent in his behavior in class and relationship with other students and teachers. The mentor/ counselor should have noticed this and acted upon it, especially having been informed of this by other students.