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Wednesday, November 11, 2026Nov 11

Report says Colorado school shooter sought revenge

Arapahoe County, Colo., Sheriff Dave Walcher answers questions after the release of new details from an investigation into a deadly shooting at Arapahoe High School last December during news conference in the sheriff's office in Centennial, Colo., on Friday, Oct. 10, 2014. Arapahoe High School student Karl Pierson fatally shot classmate Claire Davis and then himself in the attack on Dec. 13, 2013. (AP Photo/David Zalubowski)
Arapahoe County, Colo., Sheriff Dave Walcher answers questions after the release of new details from an investigation into a deadly shooting at Arapahoe High School last December during news conference in the sheriff's office in Centennial, Colo., on Friday, Oct. 10, 2014. Arapahoe High School student Karl Pierson fatally shot classmate Claire Davis and then himself in the attack on Dec. 13, 2013. (AP Photo/David Zalubowski) Arapahoe County, Colo., Sheriff Dave Walcher answers questions after the release of new details from an investigation into a deadly shooting at Arapahoe High School last December during news conference in the sheriff's office in Centennial, Colo., on Friday, Oct. 10, 2014. Arapahoe High School student Karl Pierson fatally shot classmate Claire Davis and then himself in the attack on Dec. 13, 2013. (AP Photo/David Zalubowski)

CENTENNIAL, Colo. (AP) – The student who killed a classmate before taking his own life at a suburban Denver high school last year wrote in his dairy that he was “a psychopath with a superiority complex,” and he hoped that the attack would start a conversation about school bullying.

Karl Pierson, 18, wrote that he planned the Dec. 13 attack at Arapahoe High School for months to exact revenge for being teased in elementary school, according to investigative reports released Friday.

“Words hurt, can mold a sociopath, and will lead someone a decade later to kill,” he wrote in a document titled “A diary of a madman.”

The victim’s parents said they hoped the shooting would prompt administrators and lawmakers to find ways to improve school safety by focusing on students’ psychological needs.

“The people of Colorado deserve more than to have to sit idly waiting for the next student in imminent crisis to harm or kill another person or themselves,” Michael and Desiree Davis, parents of 17-year-old Claire Davis, wrote in a statement.