Brennan Linsley / The Associated Press
Arapahoe High School students hug at a tribute site for severely wounded student Claire Davis, who was shot by a classmate during a school attack six days earlier at Arapahoe High School, in Centennial, Colo., Thursday Dec. 19, 2013. On Thursday, students were allowed back into school to retrieve their belongings.
On the morning he walked into Arapahoe High School and shot a schoolmate in the head before killing himself, Karl Pierson went bowling.
That detail — offering a chilling connection to the 1999 Columbine High massacre just eight miles away — and others about the Dec. 13 school shooting in suburban Denver were shared Monday at a morning news conference.
Arapahoe County Sheriff Grayson Robinson said Pierson, 18, planned and carried out the shooting on his own, likely motivated by a dispute with his former debate team coach.
“There is no question that this was a very deliberate and planned event,” he said, adding that evidence thus far in the investigation did not suggest any “direct or indirect co-conspirators.”
The sheriff said Pierson began the day as he normally would and “gave no indication that anything was amiss,” adding that Pierson took the time to eat breakfast and go bowling alone before heading to the school.
Arapahoe County Sheriff Grayson Robinson says suspected gunman Karl Pierson "took time to eat a meal and go bowling" before opening fire inside Arapahoe High School on Dec. 13.
That detail prompted comparisons to the Columbine High School shooting 14 years earlier. The shooters, students Eric Harris and Dylan Klebold, killed 13 people and injuring 24 others before committing suicide on April 20, 1999. They originally were alleged to have attended a bowling class in the hours before the attack — an action made infamous in Michael Moore’s documentary, “Bowling for Columbine.”
Investigators later found the shooters had not attended the class that morning.
Robinson said there was no direct evidence Pierson was inspired by or had interest in the Columbine massacre.
After making a final stop to purchase more ammunition, Pierson arrived at the school and entered through a door set ajar that was supposed to be locked, but usually was not.
Robinson urged that this was standard protocol at the school and that Pierson would likely have found a way to enter the school regardless because he was "intent on executing his violence and his evil.”
Upon entering the school on its north side, armed with a shotgun, machete, 125 rounds of ammunition and three Molotov cocktails, Pierson fired one round randomly into the hallway of the school before shooting a fatal second round that killed senior Claire Esther Davis, 17.
Pierson then fired another random shot before making his way into the school’s library and media center. Robinson said Pierson then fired one round into the area surrounding the office of school librarian and debate team coach Tracy Murphy, believed to be his intended target.
Arapahoe County Sheriff Grayson Robinson says the door suspected gunman Karl Pierson used to enter the school was supposed to be locked but rarely is because it's inconvenient.
He then ignited a Molotov cocktail in the center of the library, setting a fire that burned four book shelves and created a large amount of smoke. He then fired a fifth round and took his own life with a single gunshot to the head.
The sheriff took time to praise the actions of the school for implementing a lockdown quickly and effectively, as well as the actions of an armed school resource officer and unarmed school security guard.
The officer, Deputy Sheriff James Englert and security guard James Mauler, both ran to the library after hearing gunshots.
“I believe strongly the reason this incident took less than one minute and 20 seconds was the result of a very effective lockdown protocol in collaboration with the immediate and timely response by the armed school resource officer and unarmed security guard,” he said, adding that he was confident Pierson knew Englert and Mauler were in his immediate area.
“Deputy James Englert is a hero, there is no question James responded heroically and he saved lives,” Robinson said.
The sheriff said that while police were still investigating, a disagreement between Pierson and the debate team coach was likely “a primary motivator and element that was critical to the murderer’s plan.”
The sheriff also extended his condolences to the Davis family.
“Claire has left an impact on my life and the life of this community,” he said.