"Violence does not solve the problem. They should see that. People, including the extremists, should see that violence does not fix anything," he said.
"Peace will fix it. They have to learn to talk with people around them, too."
Atacocugu said he was heartbroken for the families of the Buffalo victims and wished governments around the world would do more to stop extremism.
"They went to do their shopping and they had no idea what's going to happen," he said.
"They were just thinking to buy their food, maybe they're feeding their young kids at home."
The 18-year-old gunman accused of killing 10 black people in the Buffalo attack had watched a copy of the livestream video the New Zealand mosque shooter had taken, according to a document attributed to him.
In a 180-page diatribe, Payton Gendron said he subscribed to the same racist "great replacement" theory that the New Zealand gunman Brenton Tarrant wrote about in a similar 74-page screed.
Like Tarrant, Gendron allegedly painted slogans on his gun and used a helmet-mounted camera to livestream his attack.
Gendron, who surrendered inside the supermarket, has pleaded not guilty and was jailed under a suicide watch.
After eventually pleading guilty, Tarrant, an Australian citizen, in 2020 became the first person in New Zealand to be sentenced to life imprisonment without the possibility of parole, the toughest sentence available.
The Christchurch attack was livestreamed for 17 minutes and viewed by hundreds of thousands of people on Facebook before it was taken down. The video and Tarrant's screed were quickly banned in New Zealand but can still be found in dark corners of the internet.
Since Christchurch, social platforms have learned to remove videos of extremist shootings faster. The Buffalo shooter allegedly livestreamed the attack to the gaming platform Twitch, which is owned by Amazon. Twitch said it removed the video in less than two minutes.
The Christchurch attacks also prompted the New Zealand government within weeks to pass new laws banning the deadliest types of semi-automatic weapons. Police paid owners to hand over their guns and destroyed more than 50,000 of them.
"We saw in New Zealand the gun control thing," said Muti Bari, another survivor from the Christchurch attacks. "We saw some measures taken by the government immediately after. We are still waiting to see what the US government does. But unfortunately, we haven't seen anything like that."
Bari, who hid in a bathroom at the Linwood mosque as the shooter killed people just feet away, said he tries not to think about that day too much but is reminded when he meets his friends, including one family that lost a father and a son.
He said the easy access to guns in the US coupled with constitutionally protected free speech — and the seeming prevalence of hate speech — was a potent mix that the US government needed to consider more seriously.
The Christchurch attack has also inspired other white supremacist shootings, including a shooting at a Walmart in El Paso, Texas, that killed 23 people.
Atacocugu, the survivor who was shot nine times, this year retraced the route the gunman drove from Dunedin to Christchurch on the morning of the attacks.
Despite his lingering injuries, Atacocugu walked and biked for two weeks along the entire 360km route. He wanted to bless the route, spread peace and change a journey that began with hate.
