Lt. Col. Dave Grossman (retired) is the author of a dozen books including best seller 'On Killing' and 'On Combat', dealing with the psychological effects of killing and war on soldiers. Grossman was a Professor of Psychology at West Point, a former infantryman, paratrooper, and graduate of the Army's Ranger School. Grossman stands alongside men such as Massad Ayoob, Jeff Cooper, and John Farnham, as a person who has begun conversations and helped laid the groundwork that the modern science of lethal force encounters rests on. Grossman is also known for his popularizing of the term 'sheepdog' referring to protectors. He also tackles controversial subjects such as video games.