Study: Police Can Transmit Abusive Behavior To Other Officers

toggle caption Manuel Martinez/WBEZ

Police officers who work with colleagues who have racked up excessive force complaints are more likely to use excessive force themselves, according to a study released Thursday that's based on a review of citizen complaints against Chicago police officers.

The study, Network exposure and excessive use of force being published in Criminology and Public Policy, suggests that problem officers can transmit bad behaviors to other cops, and that departments might be able to reduce excessive force incidents by keeping such officers away from colleagues, particularly young and inexperienced officers.

Northwestern University professor of sociology Andrew Papachristos is the senior author of the study. In prior research, Papachristos has examined the way social networks predict and influence violent crime.

"I think one of the things that we learned in the past work is that ... deviance and delinquency is a group behavior. And the same is true with police," Papachristos said.

To analyze police networks, Papachristos and his fellow researchers reviewed more than 30,000 complaints obtained by the nonprofit Invisible Institute, and focused specifically on complaints filed between 2007 and 2015 that alleged some use of force by an officer.

Based on those records, researchers found that the more an officer encounters cops with prior "use of force complaints," the more likely it is that the officer will be named in a subsequent use of force complaint.

"Similar to the ways that networks have been shown to influence criminal behavior in other contexts, our findings highlight one way social networks may shape deviance within police departments: through exposure to deviant officers," the study reads.

Papachristos and his co-authors reason that individual officers learn different forms of misconduct through interactions with fellow officers, and that working with colleagues who have a history of complaints gives officers the impression that there are no consequences for bad behavior.

"[Police] go through these trainings, but at the same time, basically every cop who's ever walked the beat or ridden in a squad car, their first day on the job someone will tell them, 'Hey, forget what you learned in the academy. I'm going to show you what it's like to be a real police officer,'" Papachristos said. "There's certain types of behaviors that you learn. And this is true of humans in general."

Papachristos said they expected to find that police social networks impact misconduct levels, but he was surprised by how much influence troubled officers could have on their peers.

Conversely, researchers found that exposure to female officers makes officers less likely to be named in use of force complaints.

That conclusion suggests that adding more female officers could reduce excessive force complaints. According to the city's inspector general, female officers make up 23% of the Chicago Police Department.

Papachristos said he hopes the study will help police leaders identify the officers who are transmitting bad behavior and take steps to prevent them from influencing younger officers.

"We are literally handing you a map of who those officers might be and who they could be influencing," Papachristos said.

And he pointed out that only a small number of officers rack up multiple use of force complaints during their careers: "If you have this small population of officers that are driving these sorts of behaviors ... we know from other sorts of interventions that you can treat a small number of offenders or a small number of people who are engaged in these behaviors and see pretty stark reductions" in the negative behaviors.

Patrick Smith is a reporter on WBEZ's Criminal Justice desk. Follow him @pksmid.