The Columbine killings
* May 21 1998: Thurston High, Springfield, Oregon. Kipland Kinkel, 15, allegedly opened fire with a semi-automatic in the school canteen. Two students died and 20 were injured. He also allegedly killed both his parents. Murder charges.
* April 24 1998: Edinboro, Pennsylvania. Parker Middle School pupil Andrew Wurst, 14, allegedly killed teacher John Gillette at a graduation dance. One teacher and two pupils injured. Charged with murder.
* March 24 1998: Westside Middle School, Jonesboro, Arkansas. Mitchell Johnson, 13, and Andrew Golden, 11, killed four pupils and a teacher. Ten were injured. Found 'delinquent' and detained by the state.
* December 1 1997: Heath High, West Paducah, Kentucky. Michael Carneal, 14, pulled a pistol from his rucksack, inserted earplugs and killed three fellow students, wounding five others. Life sentence without parole.
* October 1 1997: Pearl High, Pearl, Mississippi. Luke Woodham, 16, killed his mother, then drove to school and sprayed the playground with rifle fire. Two girls died, seven were injured. Jailed for life.