Scott Sperry jotted his name down on a sign-up sheet.

The 22-year-old student at Utah Valley University had watched Charlie Kirk's videos for years and credits the conservative firebrand with being a catalyst in his own political involvement.

Now, on this Thursday afternoon, moments before his political hero was about to speak on campus, Sperry thought it was time for him to pay it forward by joining his school's chapter of Turning Point USA - the organisation Kirk co-founded in 2012 to advocate for conservatism on college campuses.

Moments after taking his front-row seat to see Kirk speak, Sperry watched in shock as a sniper bullet rang out and blood started pouring from Kirk's neck. The images, he said, he still can't shake, but he thinks the loss will only strengthen the movement Kirk inspired him to join.

"When you try to silence a voice like this, they don't go away - you only amplify it," sophomore Scott Sperry said. "There are now going to be a million Charlie Kirks, and I feel like that's the thing that we need to do."