It’s a white guy who says it first.

It’s Saturday evening at the high school stadium, hours after a terrorist gunman killed 22 people and left dozens wounded at the Cielo Vista Walmart in El Paso. A prayer vigil has concluded, and a small group of mourners linger to try and make sense of it.

One by one they tick off the reasons: weak gun laws, a complacent Congress, a president who stokes racism and xenophobia. Aside from David Williams, they’re all Hispanic. But it’s Williams who adds: “It’s a clash of cultures, it’s Hispanic versus white.” Everyone nods in agreement.

While it was racism that compelled the shooter to draft a hate-filled manifesto aimed at Hispanics, racism that pushed him to drive 10 hours to the border and attack a community over 80% Latino, the shooting served to highlight the starkly different cultures that came together that day: one culture comprising large extended families living in close proximity and with strong religious ties, and another more fractured and isolated in the sprawling suburbs of the Dallas-Fort Worth metroplex.

All day, Williams, a local surgeon, has been hearing the same thing from his neighbors and fellow El Pasoans: “This kind of thing would never happen here,” meaning someone from El Paso would never carry out such an act of mass violence. His wife, Elizabeth O’Hara, a former journalist who is Hispanic and grew up in El Paso, has even told him: “Brown people don’t do this kind of thing.”

Now, standing next to her husband, she adds: “I finally had to ask him, ‘What is wrong with your people?’”

The question had been bothering him long before she asked, he says, particularly every time a lone white male opened fire on a large group of people. And while Williams is no sociologist (he’s a podiatrist), his own experience marrying into a large Hispanic family in a predominantly Hispanic city had given him perspective into this particular tragedy.

White people, he says, have spent the last half century closing themselves off in the suburbs, originally to separate from minorities. In the process, our families have fractured and gotten smaller, our visits less frequent, until the only time we see our extended kin is on Facebook or at funerals. Williams is speaking from his own family’s experience, but it’s similar to mine and that of many white Americans.

“But that is not El Paso,” Williams says. “El Paso is exactly the opposite. Here you’re gonna have your parents, grandparents, cousins, aunts and uncles always around, whether you like it or not. Most families see each other on a weekly basis, if not more. On the weekends, you can drive by any El Paso park and they’re full of Hispanic families cooking out, listening to music, playing volleyball, just being together. You rarely see a white family doing that.

Jose Ozuna installs American flags next to crime scene tape at a makeshift memorial honoring victims outside the Cielo Vista Walmart in El Paso. Photograph: Mario Tama/Getty Images

“It’s very hard for a member of that community to not feel supported,” he adds. “There’s always someone to talk to. White kids, on the other hand, are talking to kids in chat groups. I do think there is a clash of cultures and maybe that’s why we don’t see darker-skinned people doing this kind of mass killing.”

The research backs it up, says James Alan Fox, a professor at Northeastern University who’s studied and written extensively on the subject, most recently in the book Extreme Killing: Understanding Serial and Mass Murder. Especially strength in community. “Mass shooters generally don’t have a strong support network,” Fox says. “People who have the support of friends, neighbors and families have a sounding board to help get them through the hard times and help give them a reality check.”

That sense of community is what brought Arturo Rodriguez back to his hometown from Las Vegas, where he lived for over 20 years while serving in the air force. In fact, Rodriguez’s daughter was attending the Route 91 Harvest music festival in October 2017 when another terrorist gunman opened fire from the 32nd floor of a nearby hotel, killing 58 and wounding more than 400 others. She escaped, he says, but the aftermath reminded him of something about where he grew up.

“I’m not saying Las Vegas isn’t strong,” he says, “but we are more family oriented here. Our religion is stronger, our values are stronger. It’s the reason I returned home.”

A woman standing near Rodriguez reminds him: “We have to remember this wasn’t someone from our community.” It’s a statement I’d hear again and again, along with: “Thank God he wasn’t Hispanic.”

By now, the lights of Juarez are flickering yellow just a mile across the border. The group pauses to look at them and O’Hara says: “We’ve been here for 400 years, long before we were part of the States. This guy doesn’t get to change our DNA in one day.”

The next day, I walk to the international bridge downtown to have a look at the border. The terrorist’s manifesto cited a “Hispanic invasion”, parroting the words Donald Trump has used over and over in his tweets and speeches, and in more than 2,000 Facebook ads seen by as many as 5.6 million Americans.

We will go forward from this night with our own manifiesto: love, inclusion, compassion, hope, justice Dylan Corbett

Like other cities along the border, El Paso has seen huge numbers of migrants crossing from Central America seeking asylum, but today I see no signs of an invasion. There’s a new 18ft metal wall snaking below the pedestrian bridge that replaced the old barbed wire. And on the bridge itself, just regular Sunday traffic: people from both sides of the border shopping at Paseo de Las Luces and eating ice cream with their kids – a fraction of the 70,000 people who cross daily to shop and work and attend college the way they’ve done for generations.

Watching them lug their plastic bags and push strollers, I’m reminded of what a man said earlier at a restaurant. “I don’t have any answers,” he told me. “But our wall didn’t stop this guy from coming here and killing us.”

When the two cultures came together that day, as Williams says, the result was more than a tragic loss of life. Others I speak with say that El Paso lost a kind of innocence. That morning at Walmart, America and its twin diseases of gun violence and white nationalism finally found their way in, and now everything has changed, especially themselves.

This is especially evident later that afternoon when I visit a local gun store. The façade of Gun Central, located along Interstate 10, is decorated in rah-rah Christian nationalism: red, white, and blue bunting, a mural that proclaims “A Savior is Born” next to a manger scene and shining star of Bethlehem. And lording itself above it all is an AR-15 assault rifle spewing fire. But inside this bunker of white “Maga” gun culture just two miles from where bodies were still being recovered, I don’t encounter the expected enthusiasts marrying God and the second amendment. Instead I find a store packed with terrified people, mostly Hispanic, buying guns for the first time.

“I’m on high alert,” says April Sanchez, who works in marketing and who along with her husband and son is buying her first weapon. “I never thought I’d carry a gun, but now I want something to defend myself.”

“This isn’t something I’m proud of,” she says. “It makes me sad and angry that I’m even here. I’m heartbroken, but I’m also afraid.”

“I just want to give us both some peace of mind,” says Denzel Oliver, 29, an army veteran who’s buying a handgun for his girlfriend, Christabelle Guzman. He adds that Saturday’s shooting “is going to change this community forever”. He points to the crowds lining up for handguns and assault rifles, high-capacity magazines and ammo, and says: “Just look, it already has.”

On Sunday evening, the Interfaith Alliance of the Southwest holds a vigil at Ponder Park for El Pasoans to come together and pray. Thousands flock to the baseball diamond, many wearing T-shirts that read “El Paso Strong” and buttons bearing the word “HOPE”.

For two hours there is prayer and singing, tears and raw, unfiltered anger at the gunman who attacked this community; the terrorist who robbed its families of its mothers and fathers, tias and abuelas, cousins and friends who held it together and would never come home again; the lonely boy from the suburbs who’d gone straight for the jewel of the culture.

But that evil would not win, not when people come together and call it by name.

“For the sake of the dead and the survivors and their families, we pray for the strength to brace ourselves for the just action ahead, to choose life and the blessing,” says Dylan Corbett, director of the community organization Hope Border Institute.

“For we will go forward from this night with our own manifiesto: love, inclusion, compassion, hope, justice – all that makes El Paso and the borderlands truly great.”