It was meant to be a vigil for Kendrick Castillo, who was killed after he charged one of the two classmates who opened fire at his school in suburban Denver just the day before.

But the gathering at a neighboring school Wednesday night quickly turned political. There were speeches by politicians and at least one activist from the gun control group Moms Demand Action.

Some students from the STEM School Highlands Ranch, where nine students were shot Tuesday, reacted with anger, walking out in protest. There were chants of “mental health” and shouts of “f-ck the media” and “f-ck this.” One student, who later took the podium, said, “We can’t be used for a reason for gun control. We are people, not a statement.”

STEM School junior Fischer Argosino, who was at the vigil, told TIME the handling of the event was “inappropriate” and “disrespectful.” He said he resents the politicization of the students who had just lost a friend and experienced the trauma of yet another school shooting.

“We needed a time to mourn his passing and kind of process what happened. Because I would say it still doesn’t feel real,” Argosino said.

The students’ anger during the vigil resulted in the Brady Campaign to Prevent Gun Violence, whose affiliate student group Team Enough hosted the event, issuing an apology. It’s a lesson that not all school shooting survivors are willing to quickly turn their grief into demands for gun control and political change like many students from Marjory Stoneman Douglas High School in Parkland, Fla.

Within a week of that shooting, which killed 17 last year, Parkland students marched on the Florida state capitol and told lawmakers, “We’ve had enough of thoughts and prayers…we are coming after every single one of you and demanding that you take action.”

Joseph Eriqat, a STEM School senior who says Kendrick Castillo was one of his best friends, says the vigil left many of his classmates angry with the intense media scrutiny and the political messages from adults not connected to the school.

“I appreciate their sentiment,” Eriqat said of his classmates. “I’m not happy that it’s being politicized so soon after the tragedy.”

This area of Colorado has experienced a great deal of suffering over gun violence in the last few decades. The STEM School is less than eight miles from Columbine High School, where 12 students and a teacher were killed by two students 20 years ago. The STEM School is 20 miles away from another Denver suburb, Aurora, Colo., where a gunman killed 12 and wounded dozens of others in a movie theater in 2012.

But the STEM School is different from Florida’s Marjory Stoneman Douglas school. It’s a K-12 charter school geared toward math and science education. The two locations’ voter habits are also different. Parkland, Fla., is in a solidly Democrat-leaning area, whereas Douglas County, Colorado voted for President Donald Trump in 2016 by a nearly 20-point margin.

Another difference between the anger in Colorado and the activism in Parkland was the role of the adults in the room, students tell TIME. In Florida last year, students led the conversation and many appeared happy to appear on camera to broadcast their grief and anger to the nation. STEM School students say they felt their home was hijacked by adults with an agenda. Many were also frustrated by some TV camera crews, who they felt were pursuing students too aggressively.

“We made it clear that we didn’t want politics, and they used his death and victims for the wrong and unfair reasons,” Noah Stickney, a former STEM student who now attends another school in the area, said. “We know what politicians want, but this was about Kendrick and all who were there. We deserve a major apology, and they said the same things we’ve heard before about guns and shootings. We’re teens and children, we shouldn’t have to solve and deal with these problems.”

A spokesperson for Colorado Sen. Michael Bennet, a Democrat who spoke at the vigil, said in a statement, “That night should have been about Kendrick Castillo and the STEM School students. They are our focus and the event should have been set up to ensure their voices were fully heard.”

Following the public backlash, the Brady Campaign released a statement that said, in part: “We are deeply sorry any part of this vigil did not provide the support, caring and sense of community we sought to foster and facilitate and which we know is so crucial to communities who suffer the trauma of gun violence.”

Argosino said that while he personally feels that the focus should be on mental health care, he recognizes there will ultimately be a conversation at the STEM School about gun control.

But, he says, first he and the other students need time to process what happened, and to mourn their friend Kendrick.

“I was surprised that they were already talking about gun control and that whole political issue,” Argosino says. “So I knew that eventually we’d get to that topic and that debate about gun control and mental health and all those things, but not so soon as the day after Kendrick’s passing.”

Correction, May 14

The original version of this story misstated Fischer Argosino’s grade level. He is a junior, not a senior.

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