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Lessons Sifted From Tragedy at Columbine

A decade after Eric D. Harris and Dylan B. Klebold fatally gunned down 13 people and wounded 23 others at Columbine High School, researchers are still sifting for answers to questions raised by the elaborate and notorious attack.

Books and studies being published to coincide with the 10th anniversary of the April 20, 1999, massacre at the Jefferson County, Colo., school probe what drove the suburban teenagers to kill 12 schoolmates and a teacher, before turning their guns on themselves. The authors of this small spate of publications look for parallels between those slayings and the dozens of other school shootings that occurred before and since, and search for ways to prevent such tragedies from happening again.

While the studies differ, what many researchers seem to agree on is that there is no single profile...