Before he walked into a Pittsburgh synagogue, professed his desire to “kill Jews” and — armed with three handguns and an assault rifle — opened fire, authorities say Robert Bowers was already radicalized.

He became an angry white nationalist who authorities say killed 11 people in an act of hate.

Since the attacks of Sept. 11, 2001, and the rise of the Islamic State, researchers intensively have studied what makes someone a terrorist and how people become radicalized. Arie Kruglanski, a research psychologist at the University of Maryland, has found that although the subject matter of their extremism may be different, the way in which neo-Nazis, the Ku Klux Klan and members of the Islamic State evolve from merely disgruntled to violently angry is the same.

“It’s the quest for significance,” Kruglanski said. “The quest to matter.”

For radicalization to occur, there are three necessary ingredients, according to Kruglanski’s research. The first is the universal need to live a worthwhile life — to have significance. People usually satisfy this need through socially accepted means, “like working hard, having families, other kinds of achievements,” Kruglanski said. Radicals instead tend to place significance on their gender, religion or race.

The second is “the narrative,” which gives someone permission to use violence. Kruglanski said the narrative is usually that there is an enemy attacking your group, and the radical must fight to gain or maintain respect, honor or glory.

The third necessary component is the community, or the network of people who validate the narrative and the violence.

Bowers had all three pillars of radicalization, Kruglanski observed.

Before the attack, “he had very little significance — odds-and-ends jobs,” and no family, Kruglanski said. His neighbors never interacted with him, and he did not seem to have many friends. He does not appear to have finished high school, and classmates barely remembered him. “But he was a white male, and that made him part of a white majority.”

Kruglanski said the immediate threat to Bowers’ significance, his white majority, was the caravan of immigrants on its way to the United States, which prominent conservatives linked to the Jewish community by suggesting that George Soros, a Holocaust survivor, was paying for and organizing the caravan.

When someone or something threatens to take away “the only kind of significance these people have,” Kruglanski said, “they are ready to sacrifice all other considerations and engage in a violent act, and pay a very dear price for it.”

Tony McAleer, a former skinhead and organizer for White Aryan Resistance, said Kruglanski’s model is “spot on.” Not only did he experience the search for significance, narrative and networking that got him into hate groups when he was young, but he sees the pattern play out in the stories of other “formers” as well.

“Although, there is some nuance,” McAleer said. “Everybody wants to belong, and sometimes there’s a little serendipity to who you meet and who accepts you.” In some cases, the group itself might help a person determine what their significance is.

Hate crimes are on the rise, hitting a high in 2016, according to the Federal Bureau of Investigation, which recorded more than 6,000 incidents that year. An independent study found a spike in hate crimes specifically around the 2016 election. When someone with radical or conspiratorial notions enters a position of authority, Kruglanski said, it can be a game changer.

“These politicians, like (President Trump), are giving the ideas credibility,” Kruglanski said. “It legitimizes the narrative. It’s no longer a despised, fringe group — it’s part of the mainstream.”

And once someone is radicalized, it becomes significantly more difficult to reason with the person. At that point, McAleer said, ideology and identity are intertwined. If you attack the ideology, you’re attacking the person.

Instead, McAleer said, the person has to first disengage from the community before deradicalization is possible. That is how he went from an active white nationalist to a father of two and co-founder of Life After Hate, a nonprofit that helps people leave radical groups. The small organization has three full-time employees in addition to its volunteers and has been overwhelmed by people reaching out for help in the last year.

“Since Charlottesville, we’ve helped about 125 people,” McAleer said. The group is working on a three-day training course to teach medical professionals and law enforcement about white nationalism and give them tools to interrupt the process before violence happens.

Preventing radicalization also requires a decline in hateful rhetoric, especially from people they admire.