In 1999 two high school students, Eric Harris and Dylan Klebold, entered their Columbine High School and proceeded to massacre their fellow students, shooting dead 12 of them alongside one teacher, before they ultimately turned the guns on themselves and took their own lives. Dave Cullen’s 2009 book, Columbine, is a harrowing synopsis of both the killers’ lives leading up to the massacre, and the after stories from the survivors.
The book features a number of eye-witness accounts that are scattered throughout and ensure that this book never stops reminding you about the horror of what occurred on the day of the shooting. There are also a number of experts who are continually cited throughout, offering their diagnoses on both Eric and Dylan, with Eric being diagnosed as a textbook psychopath and Dylan as an angry depressive.
Whenever a high-profile shooting happens, a lot of mythos can get built up around it and the rumors can start to fly, sometimes being perpetuated by the media. Columbine also takes aim at those rumors, debunking some of the more circulated ones so that only the objective truth about that happened remains (Wikipedia entry).