Unsurprisingly, Radley Balko has the best and most measured take on the timeline in Ferguson and the mistakes that cops made in overzealously controlling civilian protests. (Read this interview with Norman Stamper if you need a sidebar.) I learned plenty from Balko, and one claim jumped right off the page. The story that protesters chanted "kill the police" was thinly sourced.

How could that be? The story was everywhere. This weekend Fox News report begins with the hook that as a crowd gathered outside the scene of Brown's death, "some people [were] even yelling kill the police." And here the problem starts, because the video doesn't really prove that, at all. One, the crowd's chants are indistinguishable. Two, Fox News' video was taken at night—but Brown was shot in the afternoon.

So who yelled "kill the police"? Let's go to the contemporary print reports, which credit the "kill the police" chant to the Associated Press. Here's where the AP got the scoop:

St. Louis County police said a large crowd confronted officers following the shooting, yelling such things as "kill the police."

ABC News, reporting independently on the story, cites St. Louis County police department spokesman Brian Schellman for the "kill" quote. So there you have it: The police department says that people yelled "kill the police," but no video has emerged of anyone saying it, despite the presence of media and countless cellphone cameras.

Four years ago, several black members of Congress said that they'd been heckled, spit at, and called the N-word on their way out of health care votes. Andrew Breitbart offered a $100,000 reward for any video proof that this had happened. No proof emerged. On the right, and more widely, the idea that Tea Partiers yelled racial slurs at John Lewis, et al. appeared to be debunked. 

So what should happen with the possible canard that the people at the first protest of the Michael Brown killing were yelling about murdering cops? We've come a ways since Sunday, but that detail definitely colored the way this story was received.