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://www.air-dc.org/cecp/guide/

Watch for Signs. . . Take Action
List of warning signs that may be present when a student is dealing with anger.
http://128.121.17.146/ncpc/ncpc/?pg=2088-6162