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DENVER — The new release of documents from the investigation into the deadly shooting at Arapahoe High School in December 2013 provides new details about the days leading up to the shooting, and the warnings the shooter gave before it happened.

We now know what investigators heard from students about Karl Pierson’s plan before the attack on December 13.

The documents make a few things clear:

  • Pierson wanted to kill a teacher
  • Pierson wanted to kill a few students
  • Pierson planned the school shooting for months in advance

There are 179 pages of search warrants that continue to raise questions about what the Littleton School District knew about what Karl Pierson intended to do and whether those in charge did enough to prevent it.

Pierson entered Arapahoe High School and shot fellow classmate Claire Davis. She died eight days after she was shot. The shooter turned the gun on himself shortly after shooting Davis. He was found dead inside the school.

According to the documents, Pierson’s mother confirmed the account of two security guards who say the shooter planned his actions well in advance.

“He said he was going to kill [teacher] Tracy Murphy,” says security guard Cameron Rust.

In September, Pierson’s mother told investigators, “Karl became very angry at Mr. Murphy because he was no longer debate captain.” In the parking lot “Karl was saying he was going to kill Mr. Murphy.”

Murphy reported the allegations to the school principal but later said he didn’t think the school district took the threat seriously.

At a news conference Friday, October 10 when the Sheriff’s Office released its final report about the shooting, school district administrators refused to defend themselves.

FOX31 Denver’s Justin Joseph attended the news conference. “Let me ask the question directly – was the school aware of threats?” Superintendent Scott Murphy answered, “I’m not speaking about individual students or parents. Thank you.”

The superintendent also refused to discuss students in the search warrants who may have known about the shooting before it happened.

The documents clearly show investigating deputies received “several tips saying some of Karl’s friends were aware of the plan.” One tip even stated on December 12 that there was going to be a shooting at the school the next day, although that person later denied it.

“We were told not to put things in writing,” security guard Cameron Rust says.

The documents also provide the official first confirmation of the security guard’s account that the shooter was researching guns. According to the warrants one student says Pierson showed her a picture of a shotgun that he had on his computer, and also showed pictures of the Newtown school shooting.

One additional thing… up until now we’ve believed the shooter never found the teacher he wanted to target, Mr. Murphy. But the report says Pierson did get one shot off at Murphy on December 13. Murphy said the bullet narrowly missed hitting him.