DOUGLAS COUNTY, Colo. — The younger of the two suspects accused in the May shooting at STEM School Highlands Ranch will be tried as an adult, according to a written decision by Judge Jeffrey K. Holmes released on Wednesday.

Judge Holmes denied a motion request by the defense to move the trial for 16-year-old Alec McKinney from adult court back to juvenile court. The decision letter came following a reverse transfer hearing that wrapped up in Douglas County court on Nov. 27. 

McKinney and his co-defendant, 19-year-old Devon Erickson, are accused in the May 7 shooting that ended in the death of Kendrick Castillo, who is lauded as a hero for joining other classmates to rush one of the two gunmen. Eight others were also shot.

During the hearing in Douglas County court, both the defense and prosecution spent a good portion of their time talking about the different sentencing options available in juvenile versus adult court. 

If convicted in adult court of first-degree murder, McKinney would automatically be sentenced to life in prison with the possibility of parole after 40 years. Under Colorado law, defendants who commit crimes as juveniles cannot be sentenced to life without the possibility of parole.

The defense argued that if ruled an "aggravated youth offender" McKinney could be sentenced to a maximum of seven years for a first-degree murder conviction. They also noted that each of the other charges he faces could result in a five-year sentence and when those are added, he could be sentenced to more than 130 years in prison.

The defense also argued during the hearing that McKinney should have a chance for redemption and pointed to his troubled childhood.

Defense attorneys also argued that McKinney had been hospitalized several times and seen numerous health care professionals, but none of them communicated with each other, which meant McKinney couldn't get the care he needed. They also argued that Erickson was the ring leader and that McKinney had been pressured into carrying out the plot.

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Prosecutors made the case that redemption is irrelevant and said there was a "a great deal of preparation" before the shooting by McKinney and his co-defendant.

They noted that McKinney fired nine shots from his weapon and said it was he who had the idea to put the guns into a guitar case to get them into the school.

"I am grateful to the victims and their families for the patience and understanding they have shown as they navigate a challenging and often-times slow justice system," District Attorney George Brauchler said in a statement. "My office will continue to do all that we can to support them during this difficult time in their lives."

Both McKinney and Erickson are charged with 46 separate counts, including two counts of first-degree murder, one count of conspiracy to commit first-degree murder and 31 counts of attempted first-degree murder.

An arraignment date for McKinney has been set for Dec. 16.

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