Jurors in the trial of Devon Erickson heard on Thursday from students and a teacher who were inside Room 107 of STEM School Highlands Ranch, witnessing 18-year-old Kendrick Castillo tackle his alleged murderer before they fled the class.

“Devon was kind of moving in and out of the classroom, but that’s not really anything strange,” testified Ethan Kutulas, referring to Erickson, 18, the defendant currently on trial in Douglas County. “He was standing at the door closest to me, kind of slightly away from it, and pointed up a gun up and said, ‘Nobody f—ing move.’ Then Kendrick Castillo slammed him against the wall and I fell to the ground.”

Christian Dean, now a student at the University of Colorado-Boulder, answered sternly and succinctly when prosecutors asked who Erickson was.

“He’s the same person in my class that opened fire,” Dean replied.

According to the students’ testimony, Erickson on May 7, 2019, brandished a gun, yelled out and fired multiple bullets around the time Castillo charged him. Kutulas and Dean both went to the ground, before running out into the hallway yelling at others to leave.

“I started yelling a warning, ‘school shooter, school shooter, run,’ ” Kutulas said. “I thought it was some kind of twisted joke. I thought this can’t be real. And then I realized it is real.”

Erickson faces 46 separate criminal charges, including first-degree murder, as well as two sentence enhancers. Alec McKinney, 16 at the time, pleaded guilty last year to murder and other charges for his role in the crime, and is serving a life sentence.

Erickson’s trial is scheduled for one month, and Thursday was the fifth day. Jurors heard from law enforcement personnel, including a special agent for the Federal Bureau of Investigation and a crime scene investigator for the Douglas County Sheriff’s Office, about their roles in the investigation. The forensic pathologist who performed the autopsy on Castillo also described her findings.

Several individuals in the classroom indicated they thought Erickson’s behavior prior to shots being fired was a practical joke.

“I thought it was fake,” special education teacher Raquel Sugrue recalled telling police. “The seniors do senior pranks, and so in some sick way I was hoping it was a senior prank.”

She was speaking at the time to the classroom teacher, and described a “nice, relaxing day” prior to the end of the school year, with the students watching “The Princess Bride” in a darkened classroom. After the gunshots ceased and she was on the ground, Sugrue shook the other teacher, Lauren Harper, who was not moving, and also noticed another student was shot.

“I had nothing in front of me. We’re literally just laying on the floor with no desks protecting, nothing,” she said, adding the gun was pointed at her.

Jurors also had a handful of questions about gunshot residue on Castillo, which Judge Theresa Slade directed to the forensic pathologist.