HIGHLANDS RANCH, Colo. — A vigil commemorating the victims of the STEM school shooting in Colorado ended in protest Wednesday evening after students said they refused to be used as pawns to promote gun control.

And a televised interview with a 12-year-old went viral, as a boy told CNN how he had held on to a metal baseball bat as gunfire rang out in the STEM School Highlands Ranch — just in case he had to confront a gunman.

The attack Tuesday, in which an 18-year-old student was fatally shot and eight classmates were injured after two students allegedly began firing, horrified people across the country as they heard about young people fighting to save lives. And it reopened deep rifts over politics and gun control in the United States.

Emotions remained high Thursday, as the suspects, identified as Alec McKinney and Devon Erickson, were expected to appear in court Friday to formally face charges in connection with the shooting. McKinney, who is under 18, is also set to learn whether he will be charged as an adult.

One close neighbor whose child shared voice lessons with Erickson described the 18-year-old suspect as a young man from a nice family who was immersed in theater.

“He always seemed like a good kid,” said the neighbor, who spoke on the condition of anonymity because of publicity around the case. “You never know what happens. Things can change quickly in teenagers’ lives.”

Seth Maisel, education director at the Town Hall Arts Center in Littleton, Colo., shared a statement from the theater confirming that Erickson had attended several summer theater camps there. The statement expressed sadness over the attack and said thoughts were with the families of Kendrick Castillo, the 18-year-old who was killed in the shooting at the suburban Denver school, “and all those affected by this tragedy.”

Eva Jarecke, 20, said she attended musical theater camp with Erickson but has not seen him for two years. She recalled that he was a talented performer, playing leading roles in a musical theater adaptation of the film “Legally Blonde” and in “Guys and Dolls.” She was so shocked he was accused of shooting his classmates that when his name first came up on the news, she assumed he was a victim.

“In between the last time I saw him and now, something really happened to flip a switch, I guess, and push him over the edge,” Jarecke said.

A car towed earlier in the week from outside Erickson’s home appeared to carry graffiti depicting a pentagram, “666” and “F--- SOCIETY,” according to a social media photo from KCNC-TV.

There was no answer Thursday afternoon at the blue, two-story home of Erickson.

Neighbors up and down the quiet block, where homes have Ring security devices and rabbits hop across well-kept lawns, opened their doors briefly but did not want to talk about the 18-year-old suspect or his family; those who did speak declined to give their names. It is a neighborhood that has had little drama until this week, when police and TV vehicles swarmed it, said a woman who lives nearby.

At the vigil Wednesday night, hundreds of people attended — students, teachers, activists and elected officials. They came to honor Castillo. A classmate said Castillo and several other students had lunged at the gunman, and stopped the toll from escalating; many gathered to honor them and to mourn Castillo.

But his classmates were moved to protest after two invitees, Sen. Michael F. Bennet (D-Colo.) and Rep. Jason Crow (D-Colo.), spoke. Many of the teenagers at the vigil — at the nearby Highlands Ranch High School — perceived the speeches as politicizing their trauma when they wanted their own voices heard.

Students stood and stormed out. Some clapped and united in chants, deriding what they saw as a “political stunt.” The school parking lot quickly filled with teenagers, cursing at the media and holding backlit cellphones in the air.

“What happened at STEM is awful, but it’s not a statistic. We can’t be used for a reason for gun control. We are people, not a statement,” one student wearing a yellow Spartans shirt said in video aired by KUSA-TV.

Earlier Wednesday, both Colorado politicians posted messages on Twitter endorsing changes to gun laws.

“We must pass common-sense gun violence laws,” Crow wrote.

“Our children deserve to live in a world where they don’t fear going to school,” Bennet tweeted, echoing the sentiment. “Something has to change.”

Castillo was killed three days before graduation. A bullet hit the high school senior as he tried to tackle the shooter.

The gathering at Highlands Ranch High, one of several held Wednesday, was organized by the Brady Campaign to Prevent Gun Violence, which has called for expanded background checks, measures such as safe gun storage and a ban on assault weapons.

“We are here to lift up the voices of victims and survivors,” a statement released by the Brady Center said Wednesday. “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.”

Paul and Balingit reported from Washington. Teddy Amenabar, Marisa Iati, Magda Jean-Louis, Susan Svrluga and Katie Zezima contributed to this report.