Students who commit serious acts of violence at school rarely do so suddenly or impulsively, experts said Friday during an annual safety conference for Baltimore County educators, held just weeks after two gun incidents unnerved the school community.
People usually know about attacks ahead of time — and most students who commit violence raise red flags for their teachers and others to see, said Detective Steve Jackson of the county Police Department.
"They've been on somebody's radar," Jackson told a group of teachers, administrators and counselors. "They've made the hairs on the back of somebody's neck stand up."
Jackson's presentation with...