Columbine High School Massacre: The FBI Files contains the actual original and declassified criminal investigation files related to the April 20, 1999 school shooting at Columbine High School in Jefferson County, Littleton, Colorado. Fifteen students and teachers were killed and twenty three were injured and shooters Eric Harris and Dylan Klebold were among the dead, having taken their own lives. They were armed with two sawed-off shotguns, one 9MM carbine, one Tech-9 machine pistol, and in excess of thirty improvised explosive devices. These two students were considered outcasts. They associated with a group who wore long black coats, combat boots and went by the name of "The Trench Coat Mafia." This publication is being published and made available now for the first time in a paperback book edition for those interested in the history of the Columbine High School Massacre.