PUBLISHED:October 31, 2022

New research by Grunwald et al. finds law enforcement agencies significantly overrepresent suspects of color in Facebook posts


An analysis of nearly 14,000 Facebook pages over 10 years shows Black suspects appeared in posts about crime at a rate 25 percentage points higher than actual local arrests would suggest.

Professor Ben Grunwald Professor Ben Grunwald

Police agencies on Facebook disproportionately post about crimes involving Black suspects, according to a new research article co-authored by Duke Law Professor Ben Grunwald. As a result, Facebook users are exposed to posts that overrepresent Black suspects by 25 percentage points relative to local arrest rates.

Examining the posts of 14,000 Facebook pages maintained by agencies over a decade, the authors found that overexposure of Black suspects occurred across crime types and geographic regions, and that it increased with the proportion of Republican voters and non-Black residents in a jurisdiction.

The findings highlight how law enforcement agencies may shape the public’s views about who commits crime by disproportionately representing members of certain groups as perpetrators, the authors write in an article published Wednesday in the peer-reviewed journal Proceedings of the National Academy of Sciences.

“Widespread exposure to overreporting risks reinforcing racial stereotypes about crime and exacerbating punitive preferences among the polity more generally,” write Grunwald, Stanford Law School associate professor Julian Nyarko, and University of Chicago Law School professor John Rappaport in the research article titled Police agencies on Facebook overreport on Black suspects.

“Our results point to one mechanism by which the state itself may reinforce racial stereotypes about crime. Prior research shows that these stereotypes, in turn, may heighten demand for the state’s penal services.”

While recent studies have found a decline in overreporting of crimes involving Black suspects in traditional media outlets, social media now feeds a large share of the American news diet. About 31% of Americans say they regularly get news through Facebook, according to a September 2021 report by Pew Research Center. Unlike traditional broadcast networks and newspapers, news on Facebook and other social media outlets is posted at the discretion of page owners and not filtered through editorial news standards.

The authors note that the scope of their research did not include identifying the causes of overexposure of Black suspects by law enforcement. But even unwitting overexposure can impose substantial social costs, they write.

"Showing people stories about crime by Black people activates racial stereotypes and reinforces cognitive associations between race and crime," Grunwald says.