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