Devon Erickson, 18, (left) and Alec McKinney (right) allegedly broke into Erickson's parents' locked gun cabinet and stole three guns before shooting up their high school
The two teen suspects in the Denver high school shooting broke into one of their parents' locked gun cabinet and stole three weapons, investigators believe.
Devon Erickson, 18, and Alec McKinney, a juvenile, allegedly opened fire on their classmates at STEM School Highlands Ranch on Tuesday afternoon.
Authorities said at the time that the two suspects had two handguns and a rifle, the latter of which was not used in the shooting.
It is believed that the two teens stole the weapons from Erickson's home on Tuesday morning, just hours before killing one of their classmates and injuring eight others.
Police believe that Erickson's parents legally purchased the guns. You must be 21 years or older to purchase handguns in Colorado.
Erickson and McKinney also allegedly spray-painted 'F**k society' and '666' on a car belonging to one of their parents and then tried to set it on fire before the shooting, according to KMGH.
Authorities are now investigating whether the suspects were trying to make the scene look as if they had been bullied at school.
High-ranking sources claimed that the shooters were motivated not just by bullying, but by revenge and anger toward the school.
Friends of McKinney revealed more details of the teen on social media, fighting back against authorities' decision to identify him as a woman and revealing that he was struggling with mental health issues.
Authorities described McKinney as a female juvenile named Maya after initially identifying the second gunman as a boy based on appearances.
Erickson McKinney, a juvenile, allegedly opened fire on their classmates at STEM School Highlands Ranch on Tuesday afternoon
Erickson was charged as an adult on Wednesday with first-degree murder in the death of 18-year-old Kendrick Castillo. He also faces dozens of attempted murder charges
But friends of McKinney have confirmed that the teen identifies as a male, is in the process of transitioning, and prefers to be called 'Alec'.
'Nothing that Alec and Devon did can be condoned, and they can't be defended. Their actions were terrible. But Alec is not a girl,' one friend wrote on her Instagram story.
'He at least deserves that respect. And I am so deeply sorry to anyone affected by their actions. Things like this can be prevented and they aren't. This is not okay.'
That same friend later took to McKinney's Instagram page and revealed both he and Erickson had been troubled.
'Devon did not do what he did because he's a liberal, or to make a statement,' she wrote. 'He did it due to internal struggles. They're both struggling with mental health issues and this is a time for awareness.'
'Alec did not do this because he's trans, but had people supported him in the way that he needed and deserved, he would not have struggled so much that he got pushed over the edge.'
Friends of McKinney shared more details of the teen on social media, revealing that he was struggling with mental health issues. He is pictured here at prom last month
One friend took to her Instagram story to confirm that McKinney identified as a man as she spoke out about the shooting
'They did a horrible thing, but please, please recognize that mental health awareness is important. Supporting LGBT youth is important. They didn't get the help they needed, and they NEEDED it.'
The friend said she knew both McKinney and Erickson personally and said they didn't shoot their classmates 'out of hatred toward others'.
'It
