Heidi Beirich has worked for the Southern Poverty Law Center for almost two decades. She oversees the organization’s yearly tally of “hate and hard-line, anti-government” groups. On Saturday, she was at the airport in Montgomery, Alabama—she was flying to New Orleans, where the S.P.L.C. is having its board meeting—when she saw a CNN report about the shooting at Tree of Life synagogue, in Pittsburgh.

“My first thought was, Oh God, this could be one of ours,” she told me by phone Saturday afternoon. The S.P.L.C. maintains an enormous database of extremists and extremist groups. When acts of violence and domestic terror take place, the group runs the suspects’ names against its database to see if there’s a match. If there is, they take that information to law enforcement, and share it with reporters and the public. I asked Beirich for her thoughts on the news coverage of acts of mass violence, and the debate over the merits of broadcasting perpetrators’ beliefs. “I understand the argument: don’t give these people too much ink, or airtime, because you’re just spreading the propaganda,” she said. “But the truth is these people are committing so much violence, and their ideas are actually influencing public policy—the Muslim ban, the immigration stuff thats going on—I don’t think you can ignore it.”

Even for Beirich and her team, who study the nexus of hate and violence professionally, this week—with the pipe bombs mailed to prominent Democrats, and the deliberate shooting of two black people by a white man in Kentucky—was overwhelming. “We’re just exhausted and stressed out, like the rest of the country is,” she said. But it hasn’t been just the past week—it’s been the past few years. Hate crimes increased in both 2015 and 2016, according to the latest F.B.I. data, and the Anti-Defamation League says that anti-Semitic incidents spiked in 2017. “To me and my staff, every day you just come to work and think, Is there going to be another one?” Beirich said. The F.B.I.’s data may not even be the full picture, she pointed out, saying, “Not every state has a hate-crime law, many that do don’t cover the L.G.B.T. population, and there’s no training for law enforcement.”

The suspect in the Pittsburgh shooting was identified on Saturday as Robert Bowers. He killed at least ten people before being arrested. He wasn’t in the S.P.L.C.’s system. “I’m not that surprised,” she said. “We try to collect everything we can about white supremacists, but this is a huge world.” Beirich’s team found Bowers’s posts on Gab, a social network popular with white nationalists and the alt-right. “Gab, where this guy was posting, is, like, four hundred thousand people,” Beirich told me. “We don’t have information on four hundred thousand people.”