Three weeks ago, life looked a lot different for Cameron Kasky.
The 17-year-old junior was an anonymous high school student before the Feb. 14 massacre at Marjory Stoneman Douglas High School in Parkland, Florida, that killed 14 students and three school staffers. Lately, though, he says he has been on the receiving end of hundreds of online death threats, allegedly made by NRA members incensed by his unflinching stance against gun violence.
The suspected shooter, identified as 19-year-old Nikolas Cruz, is in custody and is being held without bond. He has not entered a plea after being charged with 17 counts of premeditated murder — one for each person he allegedly killed.
Kasky has committed himself to advancing legislative changes that will make it more difficult for people to get guns, and in the process, has helped inspired advocacy around the cause.
Here are five things you need to know about the young activist.
1. Kasky Founded the #NeverAgain Movement
Within days of the deadly shooting he survived, Kasky founded the #NeverAgain movement on Twitter. It calls on lawmakers to introduce and enact legislation mandating stricter background checks for people who want to purchase firearms.
Kasky and his friends, including David Hogg, a reporter for the school paper, and Sarah Chadwick, whose indignant tweet to President Trump calling for government action on gun violence went viral, gathered together to discuss their response to the violence, and #NeverAgain took shape. Ever since, the group has been speaking with media outlets, pushing for gun safety nationwide.
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“I am really hurt by this,” Kasky told PEOPLE days after the mass shooting. “The reason I think this time is different is because it’s Parkland and it’s Douglas. … Parkland and Stoneman Douglas were able to stay strong together. That’s the thing that’s keeping us going. Together. Everybody is together.”
2. He Challenged Sen. Marco Rubio at Town Hall
On Feb. 21, Kasky participated in a CNN-produced Town Hall held in Sunrise, Florida. Kasky drew the most applause during the event with his tough questions to Sen. Marco Rubio.
The student asked the politician if he’d reject future donations from the NRA; Rubio seemed to deflect, saying he had no control over who buys into his agenda.
In a guest post written for CNN, Kasky discussed gun safety and challenged lawmakers to take quick action.
“The shooter is not the only one responsible for this tragedy,” he wrote. “While the alleged shooter may have had several issues, he also lived in a society where Sen. Marco Rubio refuses to take responsibility for the role gun culture may have played in this tragedy. And there is no denying that the NRA continues to donate millions of dollars to politicians at every level of government. Then those politicians — often “family values” conservatives — rile up their base by making them think that “liberals” are going to take their guns away. Not knowing any better, some of these people stockpile guns in advance of a gun ban that never comes, and the gun manufacturers and the NRA make millions.”
3. He Said He Left Facebook Because NRA Members Were Sending Him Death Threats
On February 21, Kasky took to Twitter to announce he was deactivating his Facebook account because he was allegedly receiving “death threats from NRA cultists.”
He did not provide any specific details about the threats.
“Temporarily got off Facebook because there’s no character count so the death threats from the @NRA cultists are a bit more graphic than those on Twitter,” he wrote. “Will be back when I have the time for it. Busy getting my feelings hurt by fellow teenagers at Br**tb*rt.”
4. He Posted About His Emotional Return to School
Over the weekend, students returned to Stoneman Douglas for the first time since the massacre for an orientation ahead of Wednesday classes. Kasky took to Twitter, posting a picture of students making there way back to the campus for an orientation organized by school officials.
“It is GOOD TO BE HOME,” he wrote, including the hashtags #MSDStrong, #NeverAgain and #MarchForOurLives.
Speaking to PEOPLE, Kasky commented on the resolve of the Parkland shooting survivors. “If we’re together, there’s no stopping us,” Kasky said. “It was like the movie the Justice League…. Alone, they could all do their thing — they could all help people. But together, it’s almost impossible to slow us down.”
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5. He Gave a Memorable Interview to CNN
In the wake of the shooting, conspiracy theorists started attacking Kasky, saying he and others who have been speaking to the media since 17 were killed at his school were “crisis actors” and that the shooting did not actually happen.
Kasky nearly stumped veteran newsman Wolf Blitzer on Feb. 21, during an on-air interview for CNN. Blitzer asked Kasky what he thought of the allegations against him. Kasky said: “Well, if you had seen me in our school’s production of Fiddler on the Roof, you would know that nobody would pay me to act, for anything.”
Not long after the massacre, Kasky spoke to PEOPLE about his resolve. “The point is Wednesday was a lot of pain,” he said. “It has been a lot of pain ever since. The only thing helping us get through the pain is the fact that this is the last time anyone is going to have to feel the way we’re feeling it.”
• With reporting by ELAINE ARADILLAS