The fact is that no one is entirely sure what kinds of violence prevention programs work best. Each school or district has its own approach. Some are geared at preventing precursors to violence like bullying; some focus on identifying at-risk students; some involve increased security and surveillance. Some programs are preventive, others reactive. Everyone tries to do what they think is practical and helpful for their school.
School policies aimed at preventing violence can relate to the carrying of weapons, drug use or bullying. "Zero tolerance" means that students found to violate the policies are immediately punished by suspension or expulsion. They send a strong message, but they may make the problem worse in some cases. Students who are repeatedly transferred from one school to another are likely to become even more resentful and prone to act out.
An instructional program is an approach that is integrated into classroom instruction, with lessons delivered repeatedly. Most instructional programs are aimed at preventing bullying and harassment, as victims of bullying are more likely to become aggressive and violent. They combine strong anti-harassment policies with lessons designed to help students think about the perspective of the child being bullied. Elementary schools engage in instructional programs more often than secondary schools.
Some programs are designed to identify and help students who appear to be at-risk for violence. They can provide individual counseling and intervention, or small group classes on anger management and conflict resolution. There are difficulties with labeling youth as at-risk, though. Very few of those who display warning signs of violence actually become so and the label itself can cause ostracization and resentment. At-risk students placed together in a group may reinforce each other's behavior.
Large urban schools, in particular, may choose to institute policies involving metal detectors and locker searches for weapons. Although these methods do result in fewer weapons being brought to school, they can also increase students' anxiety and do not address the psychological causes of violence. Increasingly, the use of campus security officers has become common. Their purpose is to put a stop to any violence before it can escalate; it is not known, however, what kind of effect armed guards may have on the mood and morale of the student body.