A year ago, Manuel Oliver thought his family had achieved the American dream. His daughter had graduated from high school in Florida. His son was close to graduating, full of plans for the great things he wanted to do. More than a decade after emigrating from Venezuela, the Olivers had become American citizens.

Then, on Valentine’s Day this year, his son, 17-year-old Joaquin, was murdered in a school shooting in Parkland, Florida.

This weekend, as an estimated 80,000 National Rifle Association supporters gather in Dallas for their annual meeting celebrating gun rights, Oliver and other survivors of gun violence will be gathering too.

Local Dallas students are organizing a counter-protest one street away from the convention center where NRA members will listen to Donald Trump again pledge his loyalty to gun rights’ advocates.

Oliver will be painting a new protest mural in Dallas to honor his son, one in a series of what he is calling “Walls of Demand” that he has assembled in different cities, including New York, Los Angeles, Miami and Springfield, Massachusetts, near headquarters of Smith & Wesson, the gun company that manufactured the military-style rifle used in the Parkland shooting.

Gun control advocates are protesting in front of city hall, rather than at the convention center where NRA members gather, because “we’re not against NRA members – we’re against the leadership of the NRA,” said Waed Alhayek, 19, a senior at University of Texas Arlington, and the executive director of StudentsMarch.org, which is organizing the rally. “We’re not going after every single NRA member.”

Alhayek was only seven when she was held at gunpoint in a neighborhood store in Detroit, Michigan, and then watched police officers confront the robber in the store and shoot him to make him drop his gun.

“My whole life, I’ve watched tragedy after tragedy happen, and I’ve waited for politicians to do something to create change,” she said. “The city of Dallas is for the people, not for the gun lobby. Having the NRA convention here was really disappointing at first, but then we realized we could use it as a platform.”

Oliver believes the NRA, with its pro-gun lobbying, is partially responsible for the circumstances that led to his son’s murder. By coming to Dallas, and speaking at Saturday’s rally, he is trying to give his son a voice and push for gun control laws, rather than a government that responds to violence by telling citizens they need to be able to defend themselves.

“Joaquin’s presence in Dallas is more than necessary. It’s mandatory,” Oliver said.

“Joaquin was my best friend, and of course he’s my son and we have that father and son relationship, but most of all, we were buddies,” Oliver said. “I know exactly what he wants to fight for, and I also know it’s totally unfair that he’s not able to be here fighting for his rights.

“There’s one thing that is for sure in America – there’s an easy access to assault weapons. We all know that, and no one seems to be fighting in that direction,” he said.

Like Alhayek, Oliver said he distinguished between the NRA’s leadership and NRA members and other gun rights advocates.

“I rather think that they’re confused than saying that they’re wrong,” Oliver said. “There’s a lot of people thinking that they’re defending the second amendment, but actually they are empowering the NRA and the business behind selling guns.”

Making a public art project in tribute to his son is an emotional effort, Oliver said, but he has seen from past experience that it is a powerful way to communicate his grief and his demand for change.

“Trust me, it’s not an easy thing to do,” he said. But “It’s also like therapy for me. It’s a relief. I have a chance to share it with my son.”

Saturday’s rally in Dallas is co-sponsored by Everytown for Gun Safety, a leading gun violence prevention group that has been staged protests at the NRA’s annual meetings each year since the 2012 Sandy Hook elementary School shooting.

The media spokesperson for March for Our Lives, the organization created by high school students from Parkland, did not respond to requests for comment about whether those young activists would be participating in any protests during the NRA annual meeting in Dallas.