Evan Long's "The Columbine Cause" is a feature-length video presentation based on public domain government records related to the official "investigation" of the Columbine High School shootings of April 20, 1999.
It includes quotations from suspect interrogations and witness interviews as recorded in little before publicized police files, 911 recordings and other rare items.
The documents reveal that many corroborating reports from Columbine High School students, faculty and others directly conflicted with the conclusions presented in the Sheriff's Office Final Report concerning the attack timeline, the weapons used and more.
YouTube - List of school shootings in the United States (Wikipedia)