In its description of Lt. Col. Dave Grossman, Slate Magazine said, “Grossman cuts such a heroic, omnicompetent figure, he could have stepped out of a video game.” He has five patents to his name and has published four novels, two children’s books, and six non-fiction books, including his “perennial bestseller” On Killing (with over half a million copies sold) and a New York Times best-selling book coauthored with Glenn Beck. He is a US Army Ranger, a paratrooper, and a former West Point psychology professor. He has a black belt in Hojutsu, the martial art of the firearm, and has been inducted into the USA Martial Arts Hall of Fame. Lt. Col. Grossman’s research was cited by the president of the United States in a national address, and he has testified before the US Senate, the US Congress, and numerous state legislatures. He has served as an expert witness and consultant in state and federal courts. He helped train mental health professionals after the Jonesboro school massacre, and he was also involved in counseling and court cases in the aftermath of the Paducah, Springfield, Littleton, and Nickel Mines Amish school massacres. After the Parkland, Florida, school massacre, he was invited to the White House as part of the President’s Round Table on Violent Video Games. Lt. Col. Grossman has been called upon to write the entry on “Aggression and Violence” in The Oxford Companion to American Military History and three entries in the Academic Press Encyclopedia of Violence, Peace, and Conflict. He has presented papers before the national conventions of the American Medical Association, the American Psychiatric Association, the American Psychological Association, and the American Academy of Pediatrics. Since his retirement from the US Army in 1998, he has been on the road over two hundred days a year for over twenty-one years as one of our nation’s leading trainers for military, law enforcement, mental health providers, and school safety organizations.