High-profile incidents of police brutality sway public opinion more than performance of local law enforcement: Study

National media coverage of police brutality influences public perceptions of law enforcement more than the performance of people's local police departments, according to data analysis from NYU Tandon School of Engineering, challenging the assumption that public confidence in police depends mostly on feeling safe from local crime.

In a study published in Communications Psychology, an NYU Tandon research team tracked media coverage of police brutality in 18 metropolitan areas in the United States—along with coverage of local crimes —and analyzed tweets from those cities to tease out positive attitudes from negative ones towards the police.

Led by Maurizio Porfiri, Institute Professor and Director of the Center for Urban Science and Progress (CUSP), the team found when high-profile cases of police brutality make the news, negative sentiment and distrust towards police spikes across cities, even if the incident occurred in another state.

In contrast, local media coverage of crimes in people's own cities had little sway over their views of the police. Porfiri discussed the research and its implications in a blog post.

"Our research shows that police misconduct occurring anywhere reverberates across the country, while performance of police in their own communities contribute minimally towards attitudes around those local police departments," said Rayan Succar, a Ph.D. candidate in Mechanical Engineering and CUSP who is the paper's lead author. "The pattern holds steady across diverse cities."

To reach their conclusions, researchers employed transfer entropy—an advanced statistical technique that allowed them to detect causal relationships within complex systems that change over time—in their analysis of more than 2.5 million geo-localized tweets. The approach allows for significantly more time-sensitive analysis of public sentiment than standard surveys which are constrained to the point in time at which they are fielded.

"By comparing this time series tracking shifts in sentiment to parallel time series documenting volumes of media coverage about local crime and national police brutality news, transfer entropy quantified causal relationships between media coverage and Twitter discourse about law enforcement," said Salvador Ramallo, Fulbright Scholar from the University of Murcia in Spain and a visiting member of CUSP who is part of the research team.

The researchers assembled their data from the period October 1, 2010 to December 31, 2020. With a time resolution of one minute, the team collected tweets in each metropolitan area that contained the words "police," "cop," or the local police department name abbreviation of the main city in the metropolitan area ("NYPD" for New York Police Department).

In that same time frame, researchers collected coverage of police brutality and of local crime from 17 of the 20 most circulated newspapers.

To better detail the interplay between media coverage and public sentiment, the researchers also zeroed in on a two-week period around the heavily-covered George Floyd murder, a notorious example of extreme police brutality. Specifically, they scraped the Twitter feeds of the top 10 most-followed newspaper profiles and created a time series of police brutality coverage from May 29, 2020 until June 13, 2020.

This highly resolved time series was examined in conjunction with the time series of negative tweets about the police for each of the 18 metropolitan areas during the same two-week time window.

"The research reveals how profoundly a single incident of police violence can rupture public trust in police everywhere," said CUSP postdoctoral fellow Roni Barak Ventura, a member of the research team. "The findings suggest that to improve perceptions, police departments may need to prioritize transparency around misconduct allegations as much as local crime fighting. More community dialogue and balanced media coverage may also help build understanding between police and the public they serve."