Police Shootings Reflect Cities’ Levels of Segregation.

In the US, a black person is three times more likely than a white person to be fatally shot by police, but this ratio varies across the country, with no difference in some places. The main reason that racial disparities in police shootings vary from one city to another is not because of individual police officers, but rather different cities’ levels of racial residential segregation, according to a new study by School of Public Health researchers.

The study, published in the Journal of the National Medical Association, finds that racial residential segregation is the predominant factor that explains why some cities have greater racial disparities in fatal police shootings—even after controlling for a city’s crime rates, black median income, racial composition of its police force, and other factors.

“Interventions such as inherent bias training aim to alter the way police officers interact with black individuals, but our research suggests that what is needed is training that changes the way police interact with black neighborhoods,” says study lead author Michael Siegel, professor of community health sciences. “Ultimately, countering structural racism itself, particularly in the form of racial segregation, is critical.”

Siegel and his colleagues previously found that states with higher degrees of residential segregation and other forms of structural racism have higher racial disparities in fatal police shootings of unarmed victims.

For the new study, the researchers used data from the Mapping Police Violence Project to examine all police shootings in 69 of the largest American cities between 2013 and 2017 to calculate the ratio of black and white victims. They found that, across these cities, a black person was 3.5 times more likely to be fatally shot by police than a white person. However, this ratio ranged widely: A black person was no more likely than a white person to be fatally shot by police in Mesa, Arizona; Honolulu, Hawaii; Lexington, Kentucky; and Henderson, Nevada—but 46.7 times more likely in Santa Ana, California.

To measure the level of black-white racial segregation in each city, the researchers used an established measure called the index of dissimilarity—in this case, what percent of black people in a city would have to move in order to produce an equal distribution of white and black people across each US Census block of that city.

They then controlled for a city’s black median income, the proportion of the black population living in rental housing, Black representation in the police force relative to the city’s racial makeup, the size of the police force relative to the city’s population, rates of crime (homicide, other violent crime, and property crime), what percent of the population is black and what percent is Hispanic, and the city’s overall population.

For each percent of a city’s black population that would have to move for an equal distribution, that city’s ratio of police shooting rates of black compared to white victims increased by 44 percent.

The researchers found that the racial composition of police forces had no impact on the racial disparity in fatal police shootings.

The study was co-authored by Rebecca Sherman and Cindy Li, research analysts in community health sciences; and Anita Knopov, who was a pre-doctoral fellow in community health sciences while working on the study.

—Michelle Samuels