DOUGLAS COUNTY, Colo. (CBS4) – On Monday, Jurors in Devon Erickson‘s murder trial heard testimony from two of his friends about his behavior before the shooting at STEM School Highlands Ranch in 2019.

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One friend, David Sispera, said he and Erickson smoked marijuana and snorted cocaine at Erickson’s house in the morning before the shooting.

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Sispera testified Erickson seemed happier and “way more positive” than he had seemed in some time.

Sispera testified that Erickson said he was going to “deal with everything” and he had a “new perspective on everything.” He said Erickson was really “amped up” and they were talking about “bettering his life.” Sispera said he had felt glad that Erickson appeared to be doing well “for once.”

After his testimony, Sispera was visibly upset.

Aaron Padgett was in Room 107 when the shooting happened. He testified that Erickson appeared “ill” to him. He also testified about a Snap Chat message Erickson sent asking him to come to the bathroom — but says he did not talk to Erickson.

(credit: CBS)

The jury had a pointed question for him — did Erickson warn him “something bad was going to happen?”

“I’m not sure, he only wanted to speak me,” Padgett said. “That’s all I knew.”

Kendrick Castillo was killed while trying to subdue Erickson after he allegedly pulled a gun in Room 107 on May 7, 2019.

(credit: CBS)

Fellow students Brendan Bialy and Joshua Jones also rushed to disarm the gunman. Jones was shot twice and survived. Bialy was not injured.

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A forensic examiner with the FBI, Cara Gregor, also testified Monday about the DNA samples taken from the guns used the day of the shooting. The DNA sample taken from the .45 caliber Glock handgun Erickson allegedly pulled on his classmates had “very strong support” that Erickson’s DNA was on the gun, which is the highest level of DNA analysis certainty that can be assigned.

The prosecution also presented compelling jailhouse phone calls Erickson made to a girlfriend months after the shooting.

In one call from Jan. 27, 2020, Erickson said, “I technically shot up the school… I don’t know, that’s pretty white.”

She replied, “what’s whiter – being a school shooter or dating a school shooter?”

In another call, Erickson’s girlfriend was asking about which kids were on the “list” for that day.

The girlfriend asked, “I wasn’t on it, was I?”

Erickson replied that “Alec was mad” at other students, saying one student in the classroom in particular “told everyone” that he and Alex had sex, and that it was “disgusting that he was trans,” so that student “was the target I guess.”

Alec McKinney, a trans boy, was the other teen charged in the shooting. McKinney pleaded guilty, and was sentenced to life in prison with possibility of parole last summer.

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Erickson’s defense claims McKinney forced Erickson to participate in the shooting.

Kati Weis