Lieutenant Colonel Dave Grossman, U.S. Army (Ret.) Director, Warrior Science Group, www.killology.com: Member, American Board for Certification in Homeland Security; Member, American College of Forensic Examiners Institute

Lt. Col. Dave Grossman is an internationally recognized scholar, author, soldier, and speaker who is one of the world's foremost experts in the field of human aggression and the roots of violence and violent crime.

http://en.wikipedia.org/wiki/Dave_Grossman_%28author%29