Inside the STEM School Shooting: A 1000-Word Report on the Tragedy of May 7, 2019

On May 7, 2019, just days before graduation, a horrific school shooting unfolded at STEM School Highlands Ranch, located in Douglas County, Colorado. The tragedy would leave one student dead, multiple injured, and an entire community forever scarred. What began as a seemingly ordinary school day ended in chaos, confusion, and unthinkable violence.

This article is a detailed account based on bodycam footage, emergency dispatch calls, and official police reports—much of which had never been seen by the public until recently.

The Attack Begins

At 1:50 PM, as students prepared to wrap up the school day, gunfire erupted inside the building. Panic swept through the hallways as calls to 911 came flooding in. Teachers and students barricaded doors and huddled in corners. Officers from multiple departments—including local police, the sheriff’s office, and SWAT teams—raced to the scene.

“Where is the shooter?” a dispatcher asked frantically over the radio.
“Room 107. We think there’s one. Maybe two. Not sure,” came the reply.

Officers didn’t wait for full tactical gear. They breached doors, smashed windows, and charged inside—knowing every second lost might cost a life.

First Confrontation and the Horrific Discovery

One of the first teams of officers forced entry into the school through a side door. Inside, chaos reigned.

“Get on the ground! Get on the ground!” an officer shouted as they confronted a potential suspect. But amidst the confusion, one of the school security guards opened fire—mistaking law enforcement for the shooter. Miraculously, the officers were unharmed, and tragedy was narrowly avoided.

As they stormed the classrooms, the scene that greeted them was like something out of a horror film: students crying, teachers bleeding, bodies on the floor.

A student named Kendrick Castillo had been shot. He’d thrown himself in front of the shooter to protect his classmates—an act of heroism that would be remembered across the nation. Officers scrambled to carry him out.

“We need a good carry! Pick him up now! Let’s go!”

Despite the urgency, confusion over how to best lift and move Kendrick led to heartbreaking delays. Officers cursed, struggled, and sprinted with him in their arms—but Kendrick would later be pronounced dead. He was just 18 years old.

Suspects Identified and Arrested

As police moved deeper into the school, they secured one of the shooters. Bodycam footage showed a handcuffed teenager lying face down, offering a strange and unsettling confession:

“I’m transgender. My breasts just flew everywhere… I flashed everyone.”

The officer responded curtly: “That’s the least of your worries right now.”

This individual, later identified as Alec McKinney, was 16 years old and biologically female but identified as male. According to witnesses and investigators, Alec had entered the classroom with a gun concealed in a guitar case and began firing.

Shortly after, police located the second shooter: Devon Erickson, 18, with distinctive purple hair, hiding in another room. He surrendered without a fight. Both suspects were students at the school.

A Community in Chaos

While officers worked to secure the school, parents arrived in droves, desperate for information. Authorities struggled to keep them back from the still-active scene.

“Do not come to the school!” dispatchers warned over the phone. “There’s an active shooter. We need to keep it clear.”

But the panic was too great. Many parents ran straight toward the school, some screaming for their children. Officers had to physically push them back. Inside, officers were still searching for more potential victims and confirming whether any other shooters were involved.

“Are there only two of you?” an officer asked Alec.

“Yes. They’re telling me to run.”

“Put your foot on me. You’re not going anywhere. You move, you get broken, you understand that?”

Inside the Classrooms

In the classrooms, terrified students had locked doors, stacked furniture, and texted final messages to loved ones. Some even filmed what they feared could be their final moments alive.

“Lock. Out of sight. Lock.” one student whispered in a video, repeating school shooter protocol instructions.

Officers systematically cleared rooms, yelling, “Hands up! Hands up!” as they entered each space. Their goal was to find survivors and identify threats without mistakenly hurting innocent students—an impossible task under extreme pressure.

Meanwhile, EMTs waited nearby. Protocols often prevent medical personnel from entering active shooter zones until they are cleared by SWAT teams. In this case, delays in reaching injured students meant precious minutes lost, and for Kendrick, it proved fatal.

Why Did It Happen?

In the aftermath, investigators pieced together a chilling motive. Alec McKinney later confessed that he and Devon Erickson had planned the attack for weeks, motivated by revenge against classmates they claimed had bullied them.

In court, Alec said he targeted specific students because he felt mistreated and wanted to make them “suffer.” He reportedly convinced Devon to join him, with both accessing Devon’s parents’ firearms to execute their plan.

Alec pled guilty to first-degree murder, attempted murder, and other charges, and was sentenced to life in prison plus 38 years, with eligibility for parole after 40 years due to being a juvenile. Devon Erickson faced similar charges and was convicted in 2021, receiving life without parole.

The Legacy of Kendrick Castillo

In the midst of this tragedy, one story stood out: Kendrick Castillo, who charged the gunman with no regard for his own safety. Kendrick’s selfless act allowed several classmates to escape or take cover.

His death drew tributes from across the country, including from lawmakers and veterans. He was posthumously awarded honors such as the Congressional Medal of Heroism and remembered by friends as a kind, intelligent young man with dreams of becoming an engineer.

His legacy now lives on in scholarships, memorials, and renewed debates about school security and gun control.

A Lingering Trauma

For the students, teachers, and first responders of STEM School Highlands Ranch, May 7, 2019, remains an open wound. In less than 10 minutes, an ordinary Tuesday turned into a tragedy that stole a life, destroyed others, and traumatized hundreds.

Survivors have since spoken publicly about PTSD, depression, and survivor’s guilt. Parents and community leaders have advocated for stricter firearm storage laws and better mental health resources.

Conclusion

The STEM School shooting serves as a brutal reminder of how quickly lives can change—and end. Despite heroic actions by students like Kendrick Castillo and the rapid response by law enforcement, one student still died, and many others carry invisible scars.

In remembering the horror, we must also remember the bravery. We must learn, adapt, and act—because no child should have to fear their classroom, and no parent should ever have to wait outside crime scene tape, praying their child is still alive.

Full video: https://www.youtube.com/watch?v=bMBIdrV-Ii4