In the days after the deadliest anti-Semitic attack in American history, Pittsburgh became a symbol of the enduring dangers of hatred, as well as the Jewish communal solidarity that followed the synagogue shooting.

Two years later, the city has become a symbol and pilgrimage site of a far more insidious sort: for white supremacists who see the Tree of Life gunman as an inspiration.

Those who monitor extremist activity say Pittsburgh has become a hub for white supremacist activity. In just the past several weeks, a white supremacist group held a march down a main boulevard there. About 100 people attended a white supremacist music festival in the area. A vocal white supremacist who had posted a call online to murder local Jews was released from prison. And flyers with white nationalist slogans have papered the city.

“We have, since 2018, seen a dramatic increase in white supremacist-related violent incidents and in the overall presence of white supremacists within our [area],” John Pulcastro, an FBI supervisory intelligence analyst, said at a symposium last week at Duquesne University’s Wecht Institute of Forensic Science and Law. His comments were first reported by the Pittsburgh Post-Gazette.

“If anyone thinks that this is not a huge issue in this area, having worked this for over 20 years, I can tell you this area is as worse as any that I have seen throughout the entire country,” he said. “It’s very, very important to understand that it is here.”

Mass shooters have long aspired to imitate previous high-profile attackers. The “Columbine effect,” in which school shooters seek to follow the example of the two teens who opened fire on a Colorado high school in 1999, has been observed more than 100 times, according to Mother Jones, a progressive magazine that documented the phenomenon.

White supremacists follow the same pattern. In their manifestos, the shooters in the attacks in El Paso, Christchurch and Poway, California, all referenced previous far-right attacks and the ideas that motivated them.

Security specialists in the Pittsburgh Jewish community say white supremacists have come to the western Pennsylvania city in part because of the synagogue shooting, which killed 11 people. The far right, they say, views the shooter as a role model — something that has already been apparent in white supremacist forums online, where they refer to the gunman by name as a “saint.”

(And he’s not alone: A T-shirt celebrating the Boogaloo anti-government extremist movement features a picture of the Poway synagogue assailant.)

“The shooter is typically revered in some of these white supremacist neo-Nazi organizations,” said Shawn Brokos, the local Jewish federation’s director of community security. “So for that very reason, Pittsburgh was placed on the map and became synonymous in many ways with white supremacy, solely based on the events of Oct. 27,” the date of the attack.

She added, “There’s momentum that has been gained due to the synagogue shooting.”