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Gun dealer Mel Bernstein holds an M-60 machine gun in his gun shop outside Colorado Springs April 27. Bernstein alerted federal authorities that school shooting suspects Dylan Klebold and Eric Harris, along
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Columbine killer's mother Sue Klebold on relationship with her son, warning signs she missed, what she went through after the tragedy - ABC News
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Columbine shooting's myths: Eric Harris and Dylan Klebold weren't Trench Coat Mafia or outcasts - The Washington Post
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