School Shooter Had Targets, Message on Arm Cops believe Karl Pierson planned to attack 5 rooms By Rob Quinn, Newser Staff Posted Dec 18, 2013 4:11 AM CST Updated Dec 18, 2013 7:35 AM CST 93 comments Comments This Sept. 7, 2013 photo shows Arapahoe High School senior Karl Pierson as he poses for his class picture in Centennial, Colo. (AP Photo/Mary McGregor) (Newser) – Colorado student Karl Pierson walked into his high school intending to kill a lot more people than just the debate coach who kicked him off the team, chilling new details suggest. Investigators say the 18-year-old entered Arapahoe High School with 125 rounds of ammunition, three incendiary devices, and letters and numbers written on his arm that corresponded to five locations inside the school, USA Today reports. He had also written the Latin phrase "Alea iacta est"—"The die has been cast"—on his forearm. Pierson, who was armed with a shotgun he bought legally, "was intent on causing the maximum amount of harm," and the Latin phrase, attributed to Julius Caesar as he crossed the Rubicon, indicates "that things have been put in motion and won't be stopped," the local sheriff says. But despite the plan, Pierson was dead within 80 seconds of entering the school. The classmate he shot, 17-year-old Claire Davis, remains in critical condition and classes at the school will not resume until next year, reports the Denver Post.