A terrifying scene unfolded at a Colorado high school Friday, just 10 miles from where the 1999 Columbine High School massacre took place. Arapahoe High School student Karl Pierson opened fire inside the building, wounding a fellow student before killing himself. Another student suffered minor injuries.
Dr. Drew and the Behavior Bureau look at Pierson, who was apparently seeking revenge against a faculty member. What went wrong with him? Was the school somehow at fault? And why is this happening in Colorado -- again?