DOUGLAS COUNTY, Colo. (CBS4)– A judge has ruled that one of two teens charged in a Highlands Ranch school shooting that killed one student and injured eight others will stand trial on all charges. Devon Erickson, 18, and Alec McKinney, 16, face murder and attempted murder counts in the May 7 shooting at STEM School Highlands Ranch.

Devon Erickson makes a court appearance at the Douglas County Courthouse on May 15, 2019. (credit: Joe Amon-Pool/Getty Images)

READ MORE: Protesters March In Denver In The Name Of 16-Year-Old Alexis Mendez-Perez

Police say the teens walked into the school and opened fire with handguns in two classrooms.

Maria and John Castillo, parents of Kendrick Castillo, seen leaving a courtroom. (credit: CBS)

Student Kendrick Castillo, 18, was killed when he and two classmates tackled one of the shooters. The other was captured by an armed security guard. Castillo’s parents attended the hearing in Castle Rock.

Kendrick Castillo (credit: Charles Burroughs)

The lead detective in the case for the Douglas County Sheriff’s Office, Brian Pereira, interviewed Erickson twice following the shooting.

He said the teen told him his goal was to “save as many lives as possible.” But under questioning by the prosecution the detective indicated there was no evidence of any such attempt to save people.

Pereira said that Erickson told him he fired only one shot by accident striking the one person who died Kendrick Castillo. But the detective indicated there were multiple shots fired from Erickson’s gun.

READ MORE: Flat Tire Causes Blue Angel To Make Emergency Landing At Great Colorado Air Show

(credit: CBS)

It was revealed that Erickson had “God” written on his chest at the time of his arrest. The words “the voices win” were found written in red ink in his parents’ closet where the guns were taken for the shooting.

Pereira also told the court “F-Society,” 666 and a pentagram were spray painted on a car in Erickson’s family garage. That car was set on fire before the pair left the house for the school.

Alec McKinney (credit: Instagram)

The detective said Erickson told him that his co-defendant Alec (birth name Maya McKinney) had someone in particular at the school to confront.

Both suspects have been charged as adults. McKinney’s attorney wants his case moved to juvenile court.

(Photo by Michael Ciaglo/Getty Images)

The preliminary hearing continued Wednesday morning with redirect by the prosecution of Pereira. The judge issued the order on Wednesday afternoon. Erickson will remain in custody on  a no bond hold.

MORE NEWS: Breast Cancer Survivors In Colorado Gather For First Time In 2 Years: 'This Is An Emotional Moment'

STORY NOTE: McKinney was born a female who identifies as male and prefers to be called Alec.