[Editor's note: This story has been updated to include comments from President Obama and additional sources.]
President Obama made an appeal for unity at a memorial ceremony held on Tuesday afternoon for the five Dallas police officers killed during protests there last week, aligning himself with the outpouring of grief and confusion that followed a difficult week for much of the nation.
The president called the shooting of the officers by gunman Micah Johnson “an act not just of demented violence but of racial hatred” and acknowledged the public’s sense that “the deepest fault lines of our democracy have been exposed – perhaps even widened.”
“We see all this and it’s hard to think sometimes that the center might not hold and things will get worse,” he said.
“I’m here to say that we must reject such despair. I’m here to insist that we are not as divided as we seem.”
Obama sought to balance his tribute to the slain officers with the claims of protestors inspired by the Black Lives Matter movement, defending the “hard and daily labor” of police while citing the “pain of Alton Sterling’s family” – a reference to one of two African-American men whose deaths at the hands of police helped spark protests after a cellphone videos of the two incidents went public.
The president’s remarks come amid a growing sense that ideological and racial strife are ascending to levels unmatched since the 1960s and 1970s.
In an op-ed for CNN published on Friday, national security analyst David Sterman and domestic terrorism analyst Peter Bergen drew parallels between the murders in Dallas and those carried out last year in South Carolina by Dylann Roof, a white supremacist.
“Terrorism is generally understood to be acts of violence conducted against civilians for political purposes,” they wrote. “Killing white police officers who are guarding a peaceful demonstration certainly qualifies as terrorism, in the same way that Roof's attack on black churchgoers does.”
US law sets three conditions for prosecution under domestic terrorism codes: the actions have to seek to influence government policy “by intimidation or coercion,” affect government conduct by “mass destruction, assassination or kidnapping,” or “intimidate or coerce a civilian population.” And the actions have to take place within US territorial jurisdiction. Typically, though, to prove intent, investigators seek to establish an individual’s link with domestic extremist groups.
In the wake of the attacks by Roof, some commentators asked why his crimes weren’t prosecuted under terrorism laws, and contended that the threat of terrorism was too readily associated in the media with Islam. Those questions may have carried extra weight given reports in recent years warning that far-right extremism posed a growing threat in the US.
In their CNN editorial, Mr. Sterman and Mr. Bergen wrote that Johnson’s murders should be a sign to law enforcement that they need to refocus their attention. “There hasn't been a case of lethal terrorism emanating from the left for more than a decade and a half,” they wrote. But in the wake of the attacks, authorities “must focus, once again, on the possibility that far-left militants may carry out lethal attacks.”
David C. Gómez, a retired FBI executive and senior fellow at the Center for Cyber and Homeland Security at George Washington University, said contemporary divisions reminded him of what he had seen growing up in the 1960s and 1970s. “I believe that these movements are cyclical,” he told the Christian Science Monitor.
But he added that he did not think that the Dallas gunman should be considered a terrorist.
“I’m kind of old school in that I think terrorism is about a message to be sent. Something that generally attacks non-combatants and the civilian population, as opposed to military or even police,” he said.
“It was a single offender who was not part of a group, and kind of had his own ideology. It’s more on the slippery slope of a psychological problem than a political problems – acting out his anger against the police.”
The Dallas shooter does not appear to have had strong ties with activist groups of any ideological stripe, as the New York Times noted on Friday, although his Facebook page indicated that he supported the New Black Panther Party, whose leaders have encouraged violence against whites, Jews, and law enforcement officers (the party is not an official successor of the original Black Panthers, some of whose founders have sharply criticized the newer group's racist ideology). The FBI is not investigating the attacks as terrorism.
Dallas authorities say that in negotiations during a long standoff with police, the gunman told them that he was angry about the killing of Alton Sterling and Philando Castile at the hands of police in Louisiana and Minnesota.
"The suspect said he was upset at white people,” said Dallas police chief David Brown, according to NBC. “The suspect stated that he wanted to kill white people, especially white officers."
John D. Cohen, a former DHS counterterrorism coordinator and current professor at Rutgers University’s School of Criminal Justice, says attacks like those in Dallas show that the threat of mass violence in the United States is changing in nature.
Over the last five years, “people are becoming inspired on their own” through social media and the internet, and without coordination from terrorist groups, Cohen told the Christian Science Monitor.
“What we are finding in most cases is that people who carry out mass attacks in the US share common behavioral and psychological characteristics” such as dysfunctional family backgrounds and underlying mental health issues. Ideological banners may be little more than window dressing. “They connect with the ideology with which they carry out their attack very late,” said Cohen.
Law enforcement, he argues, need to adjust their approach from prosecution to one incorporating a “behavioral risk assessment” long used by the Secret Service and working more with local mental health providers and community leaders to intervene before an attack.
Recent attacks might take on the appearance of terrorism in some ways. But as those in Orlando and Dallas illustrate, Cohen said, the threat may not “neatly fit legal definitions”.
Some civil liberties groups say that the definition of terrorism in US law is too broad and could allow the government to prosecute peaceful groups of a marginal political orientation. And in the years following 9/11, an analysis showed in 2009, federal agencies often disagreed over what could be considered terrorism, with assistant US attorneys declining to prosecute over two-thirds of all cases recommended for charges by investigators.