Stanford researchers study how to reduce deadly police force in Rio de Janeiro

Stanford researchers seek better strategies to control the lethal use of police force in Rio de Janeiro, Brazil. Their findings offer implications for police and communities elsewhere, as the researchers are studying how social and psychological factors affect police and how body-worn cameras can be used most efficiently.

riot police in Rio de Janeiro, Brazil

Stanford researchers are studying the use of force by police in Rio de Janeiro, Brazil, to better inform strategies for curbing aggressive behavior by law enforcement there and elsewhere. (Image credit: Agencia Brasil)

In striving to understand and to curb the use of lethal force by police in Rio de Janeiro’s poorest neighborhoods, Stanford researchers seek to help inform the widespread debate about police conduct and behavior.

Beatriz Magaloni, an associate professor of political science at Stanford, is leading an international research effort to understand why Brazil’s Rio de Janeiro has one of the world’s highest police-on-civilian fatality rates. Her research shows that between 2005 and 2013 there were 4,707 police killings and 17,392 homicides for a total of 22,099 violent deaths in Rio.

“In many developing countries, the police institution is exceedingly dysfunctional,” said Magaloni, a senior fellow at Stanford’s Freeman Spogli Institute for International Studies.

“Either cops are corrupt and work in partnership with organized crime, are poorly staffed and trained, or they abuse their power, including using torture and excessive lethal force,” she said.

Magaloni points out that violence is an obstacle to progress, peace and prosperity in developing nations like Brazil. But police-involved deaths are not limited to developing nations. She cited recent minority deaths at the hands of police in U.S. cities, including Chicago; Ferguson, Missouri; and New York City, as an indication that police everywhere sometimes act too aggressively. And so, strategies that can be used anywhere – like body-worn cameras on police – are part of her study.

Understanding police behavior

In 2013, Magaloni created the Stanford International Crime and Violence Lab, which designs research-based strategies to control violence, a central challenge for poverty alleviation in areas like Rio de Janeiro. Support for the research came from Stanford’s Global Development and Poverty Research initiative.

The Rio research has emerged from that effort. For their project, Magaloni and her team have partnered with the Minister of Security and the Military Police of Rio de Janeiro, and nongovernmental organizations working in the city’s slums. So far, this involved more than 100 interviews and focus groups with police officers and citizens. The researchers also conducted a survey of 5,000 officers, or 20 percent, of the Rio de Janeiro police force.

“The goal is to advance knowledge about police behavior and violent crime, as well as provide feedback to policymakers in Rio de Janeiro to design better strategies to control police violence and homicides,” Magaloni said.

Most victims of police violence have been young black men living in the slums, the researchers found. Also, police killing rates were five times higher in the poorest parts of Rio than in the wealthiest areas.

Community bonds critical

The researchers found that one promising reform already enacted by the government is “proximity” policing. This involves assigning newly graduated police officers trained to not reflexively engage in shootouts to the poorest areas of Rio. Also called “Pacifying Police Units,” this initiative significantly reduced police killings of civilians in the areas studied.

“Police killings in the favelas [slums] would have been 60 percent higher without the Pacifying Police Units, which means that the reduction in police killing can largely be attributed to the proximity policing strategy,” Magaloni said.

Another problem is police deaths while on duty, which have doubled since 2011. She attributed the increase to poor relationships between police and their communities.

“Police officers often treat citizens with disrespect, and racial stigmatization is common. Hence, favela residents do not trust police officers and seldom offer cooperation, including giving information to the police about suspects and violent criminals in the community,” Magaloni said.

But the consequence is that a police force that feels vulnerable is more likely to use lethal force, she added.

Magaloni’s team is also studying how many bullets individual police officers used in their daily shifts during the 2005-2014 period. Other variables under review include officers’ age, gender, training and the effect of promotions.

One big issue is how police units encourage “violent subcultures,” she said. This point was recently made clear when five adolescents were killed by Rio police officers in a unit infamous for its violent history and reputation.

“Using a variety of statistical methods, including network analysis, our research will be able to better understand how violent subcultures are engendered and how easily these can spread across units,” Magaloni said.

Violence breeds violence

Prior research shows that violent societies tend to produce violent police forces – whether in Rio or elsewhere, Magaloni said.

“One of the most revealing aspects of the survey research is that police officers in Rio de Janeiro have been exposed to high levels of violence during childhood,” she said.

According to Magaloni’s research, during their childhood 18 percent of Rio police officers saw a homicide, 32 percent had a person close to them killed by a criminal, 25 percent were constantly surrounded by gunshots and 20 percent were afraid of being killed when they were children.

Such experiences have long-lasting psychological effects on people who become police officers, she said.

In Rio, Magaloni said, police often use the “resistance to arrest” defense in cases of civilian killings, which has exacerbated the violence problem. In fact, during the late 1990s, the government introduced a “bravery bonus” that financially rewarded police officers if they engaged in shootouts with so-called “criminals.” Parts of Rio are known as havens for drug traffickers and criminal gangs.

The bonus program has been terminated, but its effects linger. Magaloni’s research revealed that police officers who received such bonuses in the past continue to use more lethal force on the job today.

Cultural and social attitudes play other roles. Forty-two percent of Rio police officers in one of Magaloni’s surveys agree with the statement that a “good criminal is a dead criminal.”

“Police killings have unfortunately been vindicated by the larger society, which has trivialized violence, especially when this affects black people in the favelas,” said Magaloni, who is also the director of the Program on Poverty and Governance for the Center on Democracy, Development, and the Rule of Law at Stanford.

Checking police aggression

Magaloni’s team suggests that body-worn cameras, which have been adopted by some U.S. police departments, could help reduce the police-on-civilian killings in Rio de Janeiro. She acknowledges that impediments exist, such as whether police officers will keep the cameras on when interacting with citizens.

As a result, her study will investigate whether it is more effective when police keep their cameras on during their entire shifts or when they only turn them on when interacting with citizens. The study will also explore the most effective protocols for processing images, which Magaloni said is often problematic for police.

“Which videos should be audited and what strategies should commanders and supervisors follow to deliver feedback to police officers?” she noted.

This study involves cameras randomly assigned among police units in Rocinha, Rio’s largest slum neighborhood. Launched in late November, it will last between nine and 12 months, she said.

“We seek to evaluate not only if cameras can reduce lethal violent confrontations, but also other forms of violent interactions, including disrespect and aggressions by the police and the community against police officers,” said Magaloni.

Finally, in 2016 she plans to begin another project with the Rio police on developing a “scorecard” that identifies the most violent police officers at all levels of their careers and randomly selects a group of these for a cognitive-behavioral intervention to practice impulse control, emotional self-regulation and developing a sense of personal integrity.

“Our research suggests that cultural and psychological factors shape police violence,” Magaloni said.

Media Contacts

Beatriz Magaloni, Freeman Spogli Institute: (650) 724-5949,
Clifton B. Parker, Stanford News Service: (650) 725-0224,