Only six months before the attack, Caleb Cain had many of the same beliefs that led the Christchurch shooter to kill 51 people.
Cain, from the US, had been sucked into the alt-right world on YouTube - by controversial far-right figure Stefan Molyneux. Eventually, though, he realised he’d been manipulated.
Shocked by the events of March 15, he started his own YouTube channel to help young people going down the wrong path.
Since then, he’s spoken to The New York Times, CNN, and PBS. On Monday he spoke to The Project's Patrick Gower.
"I went online to find ways to fix myself - to fix my depression, my anxiety, [and] to improve my life," Cain said.
"Through that, I ended up finding a content creator that you know - Stefan Molyneux.
"He became someone I looked up to, who I took advice from. I just ate every word that the man dished out."
Molyneux is a far-right Canadian broadcaster - notorious for propagating debunked pseudo-science about non-white people being genetically inferior, along with making countless comments considered Islamophobic, misogynistic and transphobic.
In 2018, Gower interviewed Molyneux and another alt-right speaker Lauren Southern after their planned gig at Auckland's Powerstation was cancelled due to backlash.
Cain said watching Molyneux lead him to view more radical content.
"I would listen to things while at work - so eight hours a day at work listening to far-right content - coming home and then probably listening to another four to six to eight hours a night," Cain told Gower.
Cain admits he thought he was "just a conservative".
"I didn't want to be a Nazi," he said. "I didn't want to be some fascist that wanted to take away people's rights."
That's when he realised he had to make a change.
"I was starting to play with the ideas of white nationalism but luckily by that point, I'd found other content creators to challenge Stefan Molyneux and all the others to help pull me out," Cain said.
Watch the full interview above.