Police disproportionately post on Facebook about crimes involving Black suspects, study finds

Law enforcement agencies on Facebook disproportionately post about crimes involving Black suspects, according to a study out tomorrow from researchers at the University of Chicago, Duke University, and Stanford University. 

The study, published in Proceedings of the National Academy of Sciences, found that the trend occurs across crime types and geographic regions, but is especially prevalent in much of the Midwest and some of the South and mid-Atlantic. It also increases with the proportion of both Republican voters and non-Black residents, the researchers say. 

The researchers gathered all posts from almost 14,000 Facebook pages maintained by U.S. law enforcement agencies, said report author John Rappaport, a University of Chicago law professor. By comparing the relative frequency of agency posts about Black suspects with local and aggregate arrest statistics, they examined whether law enforcement agencies expose users to an accurate representation of the interaction between crime and race. 

For example, Rappaport says, if 10% of people arrested in Chicago are Black and 25% of the crime posts on the Chicago PD’s Facebook page feature Black suspects, this would suggest that Black people are overreported by 15 percentage points. 

What the researchers actually found was more dramatic, even after down-weighting crime posts Facebook users saw from police agencies outside their local community.

“You can cut the data in a lot of different ways, but if what you’re concerned about is what the public is seeing relative to the reality they live in, they are, on average, seeing a representation of Black suspects that’s 25 percentage points higher than the reality they live in,” says Rappaport, who coauthored the study with Ben Grunwald, of Duke University School of Law, and Julian Nyarko, of Stanford Law School.

The researchers also found that 25 percentage-point overexposure of crimes with Black suspects in counties where Republican candidates won 75% of the votes. 

This overexposure has real consequences, Rappaport says. Law enforcement agencies may be promoting bias and advancing stereotypes in the way they use Facebook to inform the public on crime. Mischaracterizing the relationship between race and crime could also result in an increased demand for punitive approaches to dealing with crime, he says. 

For better or worse, Facebook is the way most people now find out about crime in their communities. Even local print and broadcast media often simply report the stories they get from local law enforcement’s Facebook page. It’s important for citizens to be informed on specific crimes, but police may need to think more about giving an accurate portrayal of crime and race over time. 

Rappaport also says that print and broadcast media can filter and shape the messages given by police public affairs departments. On social networks, no such filtering takes place. Users receive messages unfiltered from police, who report crime how and when they want.

Rappaport points out that the research does not address the reasons for the misreporting. It could be the result of racism within law enforcement agencies, he says, but it could also be that people who run police Facebook pages are somehow over-indexing on the kinds of posts they think their audience wants to see.