- Devon Erickson, 18, and a juvenile female were taken into custody following the shooting at STEM School Highlands Ranch in Denver on Tuesday
- The Douglas County Sheriff's Office had initially identified the female as a boy
- They are accused of storming two classrooms and opening fire with two handguns that were concealed in a guitar case
- Erickson was charged on Wednesday with murder and attempted murder, while his accused accomplice is being charged separately as a juvenile
- Kendrick Castillo, 18, was killed in the shooting and eight others suffered gunshot wounds
- Castillo, who was three days from graduating, was among the three students who tried to tackle one of the shooters when they stormed in
- Three of the injured remain in intensive care, while the five others were released from hospital by Wednesday morning
The two students accused of opening fire on classmates at their Denver high school have been revealed as an 18-year-old boy and a young girl - as authorities say the 18-year-old student who was shot dead was due to graduate in just three days.
Devon Erickson, 18, and a juvenile female - who authorities previously identified as a boy - were taken into custody following the shooting at STEM School Highlands Ranch in Denver on Tuesday afternoon.
Erickson was charged as an adult on Wednesday with first-degree murder and attempted murder ahead of an initial court appearance in the afternoon. His accused accomplice is being charged separately as a juvenile.
The Douglas County Sheriff's Office said they had initially believed the female shooter was a male based on appearances and were not able to confirm her gender until an interview had taken place.
The underage student is reportedly in the process of transitioning from female to male but Sheriff Tony Spurlock would not confirm if the young suspect was transgender.
'Right now we are identifying the individual as a female, because that's where we're at,' he said. 'We originally thought the juvenile was a male by appearance.'
Devon Erickson, 18, has been identified as one of the two suspects who allegedly opened fire on STEM School Highlands Ranch in Colorado on Tuesday afternoon
Kendrick Castillo, 18, was killed when the two students stormed into two classrooms and opened fire with handguns that were concealed in a guitar case.
Eight students suffered gunshot wounds in the shooting and three of them remain in intensive care in hospital. Five had been discharged from the hospital by Wednesday morning.
Authorities have not yet released a motive for the shooting, which occurred just miles from the scene of the deadly 1999 Columbine High School massacre.
Kendrick Castillo, 18, died on Tuesday afternoon when two students stormed STEM School Highlands Ranch in Denver and opened fire with at least two handguns
Castillo, the 18-year-old student who was shot dead, was just three days away from graduating, according to Douglas County Sheriff Tony Spurlock.
Classmates said Castillo was among a group of three students who tried to take down one of the shooters by tackling them when they stormed the classroom.
The father of one of those heroic students, Brendan Bialy, told the New York Times that the trio tackled the shooters when they entered the classroom 'and one pulled a gun out of a guitar case'.
He said 'his son and two friends tried to tackle the gunman but one of the boys was shot in the chest'.
'We're going to hear about very heroic things that have taken place at the school,' Sheriff Spurlock said.
The two suspects opened fire in two separate classrooms in the high school section of the campus, which serves grades kindergarten through 12th.
Authorities said they went into the school through an entrance without metal detectors.
They were arrested within minutes after administrators reported the gunfire, according to Sheriff Spurlock.
Spurlock said officers engaged the suspects and there was a struggle to bring them down but neither suspect was injured in the confrontation.
Authorities recovered three handguns and a rifle but said the latter was not used in the shooting. The two students were not old enough to buy or own the handguns.
Terrified students were evacuated from the school after shots were fired at 1.53pm
Fernando Montoya (above with his daughter) said that his 17-year-old son was shot three times but was expected to make a full recovery
Authorities were seen outside a home in Highland Springs believed to be owned by Erickson's parents, James and Stephanie, on Tuesday night
Car towed from #stemshooting suspect's home apparently has "F*** SOCIETY" spray painted on the side. Also "666" and a what looks like a pentagram sprayed on the hood.
Douglas County Sheriff Tony Spurlock said Devon Erickson, 18, and a younger student walked into the STEM School Highlands Ranch through an entrance without metal detectors and opened fire with two handguns on students in two classrooms
Authorities were seen outside a home in Highland Springs believed to be owned by Erickson's parents, James and Stephanie. The mother's Facebook page was deleted shortly after news broke of the shooting.
A car spray painted with the words 'f*** society' was towed away from the house at around 10pm.
A criminal background check revealed Erickson's almost unblemished record, which noted a ticket for careless driving issued in Douglas County on February 13, 2018.
His mother broke down in tears on Wednesday and said she didn't know why her son opened fire on classmates, theNew York Postreports.
The teen's social media pages indicate that he is an avid guitar player, youth theater actor and registered Democrat who has on occasion expressed disdain for Christians, criticized President Donald Trump and praised former President Barack Obama.
In a post from 2014, Erickson wrote: 'You know what I hate? All these Christians who hate gays, yet in the bible, it says in Deuteronomy 17:12-13, if someone doesn't do what their priest tells them to do, they are supposed to die. It has plenty of crazy stuff like that. But all they get out of it is 'ewwwwww gays'.'
In 2015 he shared a Facebook post by Occupy Democrats praising Obama, and in 2016 shared a video of TV host Seth Meyers criticizing Trump.
Erickson also has a YouTube channel where he posted videos of himself playing the guitar.
His Snapchat account is reportedly under the name 'devonkills'.
In one Instagram post obtained by Heavy.com, Erickson wrote: 'I'm covered in ink and addicted to pain.'
In another from 2018 he said: 'I'm only posting one of my senior pictures so people don't think I dropped out since I don't take classes at stem anymore.'
A combination of factors, including revenge and anger, spurred the attack, the Denver TV ABC affiliate reported, citing law enforcement sources. One of the suspects had reportedly been bullied over gender identity.
Erikson was charged on Wednesday as an adult with murder and attempted murder
The teen's social media pages indicate that he is an avid guitar player and a youth theater actor. Erickson also has a YouTube channel where he posted videos of himself playing the guitar