Dzhokhar Tsarnaev's loyalty to brother, teen brain were explosive combination. April 23, 2013 — -- Dylan Klebold, the depressed senior at Columbine High School, had Eric Harris. Washington, D ...

Eric Harris (l.) and Dylan Klebold, carrying a TEC-9 semi-automatic pistol, are pictured in the cafeteria at Columbine High School, in Littleton, Colo., during their shooting rampage.

Dylan Bennet Klebold was born in Denver, Colo., on Sept. 11, 1981. He was the second child of Thomas and Susan and the brother of Byron, three years older.

And Klebold talks of a survey indicating that “83 percent of respondents said that the parents’ failure to teach Dylan and Eric proper values played a major part in the Columbine killings.” ...

The mother of Columbine shooter Dylan Klebold says ina new book that she prayed for him to commit suicide when she was told he was a suspect in the attack. Nov. 17, 2012, 10:42 PM EST / Source ...

On April 20, 1999, Dylan and Eric Harris opened fire at Columbine High School in Littleton, Colo., killing 12 students and a teacher, and wounding 24 others before taking their own lives.

For nearly two decades, Sue Klebold has tried to wrap her head around why her son 17-year-old Dylan, along with Eric Harris, 18, killed 13 people in a mass shooting at Columbine High School in 1999.

S ue Klebold, mother of Columbine shooter Dylan Klebold, spoke out about the guilt she still lives with over her son’s deadly attack in an emotional interview with Diane Sawyer Friday night ...