Clearly articulating the threats the son is receiving at school. A letter must be sent to the school principle, a copy to the school teacher and another copy must be sent to the superintendent of the school district. In this letter the parent should not only describe the situation and their concern but for immediate assistance in addressing this act of violence. If the parent doesn't receive a suitable response within a few weeks, the parent must then send another letter to the State Department of Education and also copy the Superintendent, the principal and the school teacher. Usually if a parent goes all the way up the chain of command to the state level, fear of lawsuits will then often act as a motivator to address a potential act of violence.
Every child has their own definition of violence and every parent has their own definition.
Oftentimes a parent and child don't share the same definition. In my book we talk about the importance of parents and children sharing the same definition. Also schools have their own definition of violence. In schools bullying, teasing, name calling could all be defined as acts of violence or threats of violence. As we move towards zero tolerance in the schools we find that we no longer can accept teasing and pushing and shoving.