DENVER — In an interview the father of Arapahoe High School shooter Karl Pierson said he still is having trouble understanding how his son could become a killer.
Karl Pierson shot and killed Claire Davis and tried to kill the debate team coach before turning a gun on himself on Dec. 13.
Friday, authorities released parts of the 18-year-old senior’s diary which described how he planned the shooting for several months.
Mark Pierson told The Denver Post Tuesday that he wasn’t aware of his son’s diary because it was kept on a thumb drive and hidden in Karl Pierson’s car.
Karl Pierson was an Eagle Scout who had a try sense of humor and could light up a room, his father said.
But according to excerpts of the diary, Karl Pierson was deeply angry and started planning violence after he was told that he could not be the captain of the speech and debate team.
Karl Pierson wrote he would “shoot up my school before the year is over” and referred to himself as a “psychopath with a superiority complex.”
“Anyone who read the excerpts from the diary or the paper can’t put those two people together,” Mark Pierson told the Post. “I can’t put those two people together.”
“I read it and I was like, ‘Wow, this is my son writing this, really?’ I just can’t believe it but that’s how angry and upset he was,” Mark Pierson said.