Colorado Shooter Planned To Attack 5 Other Spots

The shooting at a suburban Denver high school by a student last week reportedly involved a plan to attack at least five more different areas, investigators said Tuesday.

Locations of the Arapahoe High School library and four adjacent classrooms were written in the form of letters and numbers with indelible marker on Karl Pierson's arm, the Associated Press reported.

Investigators suspect Pierson planned to target those spots, Arapahoe County Sheriff Grayson Robinson said in a statement. It has yet not been determined by the investigators whether the occupants of those rooms were personally targeted by Pierson, according to AP.

A librarian who headed the school's speech and debate team was believed by the investigators to have been Pierson's intended target on Friday, Robinson had said previously.

But Pierson planned to harm others as well.

According to AP, the librarian escaped, but Pierson critically wounded a 17-year-old senior, Claire Davis, whom he encountered soon after entering the school armed with a 12-gauge pump-action shotgun, a machete and three Molotov cocktails.

Pierson shot Davis in the head point-blank while she was sitting with a friend near the school library. She presently remains in a coma.

Eighty seconds after entering the school, Pierson ended up killing himself in the library with his sixth and final shot as a school resource officer was closing in, AP reported. Also written on Pierson's arm was the Latin phrase "Alea iacta est," which translates to "The die has been cast."

Details on the amount and type of ammunition Pierson carried were provided by Robinson on Tuesday. He had more than 125 rounds of steel-shot, buckshot and slug ammunition on him, AP reported.

Pierson's parents said they are "shattered" by the tragic events, and are praying for victim whom their son shot.

"Our thoughts and prayers are with Claire Davis and her family. They, and she, have suffered unimaginably, and we pray for her full recovery. We also pray for the entire Arapahoe High School community, as we know your lives are forever changed by this horrific event," Barbara and Mark Pierson said in a statement issued Monday. "As parents, we loved our son Karl dearly and we are devastated by what happened Friday. We cannot begin to understand why Karl did what he did. We ask for privacy during this unthinkably difficult time and hope that you will respect our need for time to grieve."