HIGHLANDS RANCH, CO - MAY 07: A bus evacuating students arrives at the Recreation Center at Northridge after at least seven students were injured during a shooting at STEM School Highlands Ranch on May 7, 2019 in Highlands Ranch, Colorado. (Photo by Michael Ciaglo/Getty Images)
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(CNN) —  

One of the first things she noticed was that her child, and other students at STEM School Highlands Ranch, weren’t getting enough sleep. The academic workload, she said, seemed crushing. The parent noticed kids stressing out, and lashing out. She said she heard reports of violence, sexual assault and bullying. Yet school officials, she said, seemed to be ignoring the mounting problems.

When she finally picked up the phone to talk to a county school board member in December, she said she was worried that a “perfect storm” was brewing “for something like a Columbine” shooting.

The woman’s concerns were detailed in a CNN story this week following a shooting at the suburban Denver school that left one student dead and eight others injured. The mother, who showed CNN evidence of her affiliation with the school but asked not to be identified out of fear of retaliation against her or her child, gave an interview Thursday expanding on her worries about the “pressure-cooker” environment on campus.

Related: District urged school to investigate concerns it could become the next ‘Columbine’ months before shooting

“When you don’t listen to parents’ concerns, when you don’t support teachers’ concerns, when you don’t give teachers the kind of training that they need or the support that they need … those are the elements that we need for the perfect storm, for something like a Columbine, or some kind of imminent threat to our children’s safety in the school, whether it be a bomb or an active shooter, or a suicide,” she said in the interview.

Following the parent’s call to the school board in December, a district official urged the school’s executive director to investigate the allegations to determine whether the parent’s fears were founded and whether any action needed to be taken.

“The concerns expressed by this individual are very serious and need to be looked into to the extent possible,” Douglas County School District official Daniel Winsor wrote in a December letter to STEM’s executive director, Penelope Eucker. “Please keep (the district) apprised of your investigation and conclusions.”

Eucker provided CNN a statement via a public relations firm on Thursday, saying STEM officials reached out to all of the school’s parents following the woman’s complaints “in the hopes that any student or family member with knowledge of the allegations would confidentially share that information.” Eucker said that the school did not receive any responses with information about the allegations.

Following the investigation, Eucker sent a letter to parents disputing the woman’s allegations and informing them that school officials had filed a defamation lawsuit against the parent, even though they did not know her identity. The mother told CNN this legal action is another reason she wanted to come forward anonymously.

Eucker did not comment on the lawsuit in her statement.

Related: This student died trying to stop the Colorado school shooter

In her statement Thursday, Eucker said “the safety and wellbeing of our students and staff is our highest priority.” She said “like any school with more than 1,800 students, we receive complaints, all of which we take seriously and investigate promptly.”

The parent said that while there are some well-intentioned teachers, she feels the school’s leadership could have done more to protect the students.

“Did kids feel aggressive toward one another and act out that aggression that I saw? Yes. That my children experienced? Yes. That their friends experienced and told me about? That I heard about from other parents? Absolutely,” the parent said. “I also feel that there was a clash of people’s ideas and cultures.”

The mother was not alone in her concerns about the school.

An online petition signed by multiple parents and a post on a Facebook page for the school district community also expressed concerns about the leadership of the school. And minutes from a “School Accountability Committee” meeting at the school describe “a small group of people who speak against STEM.”

District officials also levied some criticism at the school, though parents interviewed by CNN said they believe the district also did not do enough to investigate parents’ concerns leading up to Tuesday’s attack.

In a letter to STEM’s board of directors last year, school district officials raised questions about “legal costs for special education matters,” saying it had received more complaints since the beginning of the previous school year than any other charter school in the district – including one that resulted in a financial settlement agreement and two that resulted in corrective action.

Another 2018 letter from the county Board of Education said it had “significant concerns” about STEM’s compliance with the charter school contract and legal requirements, and questioned its willingness to serve students with disabilities. It also cited “ineffective leadership,” saying, “the tenor of the comments at our meetings suggests that the relationship between STEM and some of its parents is irretrievably damaged.”

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