When in doubt, mace the black guy

It turns out that, for decades, protests with black participants were more likely to meet with a police presence. And at events the police do show up for, they're more likely to arrest or beat protesters when at least some of the protesters are black.

These findings come from a 2011 paper coauthored by professors at Notre Dame, Stanford, and the University of Wisconsin. The professors — Christian Davenport, Sarah Soule, and David Armstrong — took a database of 15,000 American protests from 1960 to 1990 and used newspaper reports to identify which protests had at least some black protesters. After controlling for some confounding variables, they compared those protests to ones with no black protesters.

The first major finding is that police were more like to show up when black people were in the crowd...

Then, the researchers looked only at protests where police showed up, comparing policed protests with some black protesters with those where were none. Davenport, Soule, and Armstrong found that "once police are present, they are more likely to make arrests, use force and violence, and use force and violence in combination with arrests at African American protest events."