The Arapahoe High School senior who shot a fellow student Friday in the school's hallways before killing himself was no longer an active participant on the debate team — possibly among the motives behind the attack.

Few details are coming out to possibly indicate why 18-year-old Karl Pierson walked into Arapahoe High with a shotgun, ammunition, a machete, Molotov cocktails and an intent to kill — but one of his friends has an idea.



But Redmond was not clear why.

Pierson was a gifted extemporaneous speaker, finishing third in a state competition in April and earning a trip to the national competition in Alabama in June. Pierson, who was Arapahoe's sole entrant in the competition, attended the event with Murphy, Redmond said.

Murphy could not be reached Saturday for comment.

In a Facebook posting in June, Pierson told his friends he failed to place in the top 60 in the competition.

At the start of this school year, Pierson was the extemporaneous captain on the school's speech-and-debate team. By October, his listing as one of the team officers had been removed from the school's website.

Arapahoe County Sheriff Grayson Robinson said Pierson and Murphy had a conflict in September and Pierson was disciplined. Robinson did not elaborate, saying only that Pierson was not suspended or kicked off the team.

Redmond was under the impression Pierson was kicked off the team. Whatever transpired between Pierson and Murphy was not disclosed to the rest of the team.

"It was all very hush-hush," Redmond said.

On Monday, Pierson approached Redmond at the school to congratulate him and the rest of the team on a successful weekend tournament at Chatfield High School, where the team finished first.

Redmond told Pierson he wished Pierson had been a part of it.

"He said, 'Mr. Murphy said I could come back.' " Redmond said. "But he said, 'I hate him so much that I can't come back.' "

Redmond said Pierson had a different idea about how the team should be run, which caused a conflict between the student and coach. But Pierson told Redmond there was another reason for their friction.

"Apparently, if you threatened to kill a teacher, you get suspended," Pierson told Redmond.

"I said, 'That kind of makes sense.' And he didn't want to talk about it anymore," Redmond said.

That wasn't the last time Redmond and Pierson talked.

They had a conversation Thursday, the day before Pierson stormed into the school building with a shotgun and shot a female student in the head before going to the library, where Murphy worked.

Twenty-four hours before Pierson's attack, he was joking and talking politics with Redmond.

"We were back to our old conversations," he said. "I have no idea what happened (over the next 24 hours). I can only speculate."

Redmond wondered whether Pierson had received a rejection letter from a college he had applied to and blamed Murphy. But Redmond didn't know that Pierson had already bought the pump-action shotgun. It was purchased Dec. 6 at a local store. He also didn't know that he had bought a large amount of ammunition.

Sheriff Robinson said Pierson took only 1 minute and 20 seconds to storm into the school, shoot five rounds, blast his shotgun at Claire Davis' head and set fire to the library with Molotov cocktails before killing himself in a corner of the library.

Davis, 17, is in critical condition at a Littleton hospital.

The only motive Pierson had, Robinson believes, was something not born in his high school or spurred by his differences with his debate coach.

"His intent," Robinson said, "was evil."

Jeremy P. Meyer: 303-954-1367, or