In 1999, Eric Harris and Dylan Klebold killed 15 people and wounded 23 more at Columbine High School. The destruction occurred despite the fact that there was an armed security officer at the school and another one nearby -- exactly what LaPierre argued on Friday was the answer to stopping "a bad guy with a gun."

Deputy Neil Gardner was a 15-year veteran of the Jefferson County, Colo., Sheriff’s Office assigned as the uniformed officer at Columbine. According to an account compiled by the police department, Gardner fired on Harris but was unsuccessful in stopping him: