STEM School Remains Crime Scene As Investigators Search Campus

HIGHLANDS RANCH, Colo. (CBS4)- Investigators continue to search STEM School Highlands Ranch where one student was killed and eight others injured in a shooting on Tuesday. The campus, which houses an elementary school, middle school and high school, remains a crime scene.

Copter4 flew over the school where a banner covered the logo above one entrance. Some student property remains in the parking lot and on campus, including bicycles.

FBI agents continue to gather evidence in the wake of the shooting. Two suspects have been arrested, Devon Erickson, 18, faces 30 counts including first-degree murder, and Alec McKinney, a juvenile. Both are scheduled to appear in court on Friday where formal charges will be filed.

CBS4 learned that Erickson was a student in the classroom where the shooting began. It was a British English class. The teacher, Lauren Harper, was seen outside the school on Tuesday, wrapped in a blanket and speaking with officers.

Her mother, Mary Pagnard, told CBS4's Rick Sallinger, "I believe a student was targeting her, from what I understand."

HOW TO HELP: Highlands Ranch School Shooting

Another student in that class, Kendrick Castillo, is said to be a hero. He pushed a gunman out of the classroom and was shot during the altercation. He did not survive.

"The people who told me what happened is that he didn't hesitate. He heard him say, 'No one move' and he jumped up and tackled him as quickly as possible," said Castillo's friend Charles Burroughs, Jr.

Investigators are gathering evidence about the suspects on social media. Erickson was a singer in a rock band and was involved in acting. He was known as "straightblades" on one account.

As for McKinney, the juvenile was born female but identifies as male.

The two handguns believed to be used in the shootings were taken from the parents of one of the defendants, according to sources.

Several months before the shooting at STEM, an anonymous call was placed to the school by a person claiming to be a parent. That call was detailed in a letter that described the numerous complaints and perceived dangers. The letter was then passed on to the Douglas County Sheriff's Office.

The school responded by filing a lawsuit against the anonymous female caller, seeking her identity. The lawsuit also claimed the letter was slander.

HOW TO HELP: Highlands Ranch School Shooting