Judge says teen to stand trial in Colorado school shooting A judge says prosecutors have enough evidence for a Colorado teen to stand trial on dozens of charges in a suburban Denver school shooting that killed a classmate

CASTLE ROCK, Colo. -- Colorado prosecutors have enough evidence for a teenager to stand trial on dozens of charges in a suburban Denver school shooting that killed a classmate, a judge ruled Monday.

Judge Jeffrey Holmes ruled that Alec McKinney, 16, should stand trial on more than 40 charges, including murder, in the May 7 shooting at STEM School Highlands Ranch.

The ruling came on the first day of a hearing that also will determine whether McKinney will be tried as an adult, The Denver Post reported. The hearing could last another week.

In September, another judge found that the 19-year-old accused of being an accomplice, Devon Erickson, could be prosecuted on 44 charges that include murder and attempted murder.

Kendrick Castillo, 18, was killed after he and two other students rushed one of the shooters in a classroom.

Interview transcripts, text messages and Snapchat videos introduced as evidence Monday portrayed McKinney as angry at being bullied because he is transgender.

After the shooting, McKinney told police he had voices in his head that made him want to shoot at the school, according to testimony about his interview with police after his arrest.

School security camera video played in court showed that after the shooting, McKinney tried to turn his gun on himself, but a security guard stopped him.

Previously released court records suggest that McKinney may have planned the attack. Written summaries of police interviews portrayed McKinney as enlisting Erickson in a plan to kill students who bullied McKinney, who identifies as male.

Erickson's lawyers have stressed that McKinney pressured him to participate.

They have not entered pleas to the charges yet.