SEATTLE -- Billy Williams, the top federal prosecutor in Oregon and an appointee of President Donald Trump, has little doubt who is behind the violence and destruction that has accompanied nationwide protests against racism by police: the ultra-left movement known as "antifa."
"At some point during each protest in individual cities, law enforcement has noticed a more organized effort," he said Monday during a news conference in Portland. "Protesters fan out and engage in the same kind of criminal conduct."
Jo Ann Hardesty, who last year became the first black woman to serve on Portland's City Council, also blames interlopers: the ultra-right hate group Proud Boys.
"We allow white nationalists and white supremacists to infiltrate our peaceful protests ... and then create the kind of chaos and damage in our community," she said in a video recording released Tuesday. "We must make that stop."
As cities reel and Trump threatens to deploy the military, figures across the political spectrum have been quick to defend their own citizens as peaceful protesters while accusing outsiders of fomenting the unrest.
But they have presented little evidence to support their allegations, and like so much in the highly polarized politics of this era, most people see what they want to see.
To hear one side tell it, thuggish white men are showing up at rallies with backpacks stuffed with rocks, pipes and other projectiles, aiming to discredit the mass movement against police brutality and gain support for their own racist agenda. On the other side, the Trump administration and its supporters say the violence is being perpetrated by anarchists who seek to sow chaos and destabilize the government.
But the publicly available evidence for both perspectives remains anecdotal -- such as an incident Monday night in Centennial Olympic Park in Atlanta.
Terrance Holt, a 27-year-old black man, was standing in the middle of a small crowd of mostly black protesters when a rock flew through the air and landed a few feet from the long line of U.S. National Guard members.
As the crowd scattered, protesters identified the rock thrower as a lone white man in dark jeans, a dark jacket, a baseball cap and a mask.