1998 Annual Report on School Safety Site offers suggestions for school to improve safety. http://www.ed.gov/pubs/AnnSchoolRept98/index.html
Early Warning, Timely Response-A Guide to Safe Schools A Guide to Safe Schools Identifies both anger and aggression as two of the many warning signs. http://cecp.air.org/guide/guide.pdf
Warning Signs - Dealing with Anger Article offers ways to deal with anger without resorting to violence. http://apahelpcenter.org/featuredtopics/feature.php?id=38&ch=5