The rate of serious injuries caused by police and private security increased nearly 50% from 2001 to 2014, according to a new study from Harvard public health researchers that looked at emergency room visits.

An article published this week reviewed hospital emergency room data to analyze non-fatal injuries following “legal intervention” – defined in this study as a wound inflicted by police officers or private security guards. In the 14-year period examined, the rate of these injuries per 100,000 people increased by 47.4%. The analysis is one of few that can provide a longitudinal study of police use of force over time, according to lead author Justin Feldman.

The article also concluded that black civilians, and particularly black men, are significantly more likely to be injured by police than their white counterparts, a trend carried over in numerous analyses of police killings and fatal shootings. Black people were injured and sought treatment at a rate 4.9 times higher than whites, according to the research.

In the 14-year period studied, the majority of injuries – 64% – were categorized as “struck by/against”, and stemmed from a physical interaction with officers. Non-fatal firearm injuries caused just 1% of the estimated 683,033 injuries.

Feldman, a doctoral candidate at Harvard, and his co-authors are part of a body of public health researchers increasingly analyzing injuries and deaths caused by police as a public health issue.



The Harvard researchers looked at trips to emergency rooms by persons aged 15 to 34, who accounted for the majority of legal intervention injuries during the time period studied.

Epidemiologist Nancy Krieger, one of the article’s co-authors, said the study analyzes a new source of data and adds to the knowledge about non-lethal police violence, which can be harder to track.

Of the steady increase in the rate of hospital admissions following force by officers, Krieger said because there is little historical data on police force, it’s “hard to know is that smaller or bigger an increase than one would expect”.

“I think the point is not necessarily how much it’s increased but the fact that it looks like the trend is going up,” Krieger said. “This is not the kind of thing that you want to see going up.”

The federal government does not track killings by police, although the Department of Justice aims to do so in a new pilot program that began last year. There is no complete set of data to indicate how police use of force has changed in recent history.

The research, published in the Journal of Urban Health, uses data from a frequently overlooked source of criminal justice knowledge: a survey initially meant to track injuries caused by consumer products. The US consumer product safety commission has long tracked data on patients with injuries related to products, and in 2000 began tracking a wider array of injury data from a representative sample of 66 hospitals across the country.

Feldman said when he began studying police use of force, he was looking for reliable sources.

“In terms of nationally representative data, this is the one,” he said, explaining that because this data is collected specifically for research purposes, it’s more reliable that data that comes from hospital records.

The article’s conclusions were limited because race data was missing for many patients, so the authors were unable to draw reliable conclusions on how likely non-black people of color were to suffer non-fatal injury compared to whites. In addition, Feldman explained, differences in how frequently racial groups seek medical treatment could affect the data.

Because the data doesn’t differentiate injuries from sworn police officers and private security guards, the group behind the increase is unknown. Feldman said he believes that police officers are responsible for the majority of these legal intervention injuries and for the increase, but can’t know for sure because so little is known about when security guards use force on the job.

Mahesh Nalla, a professor at the school of criminal justice at Michigan State University, said there was no data he knew of tracking lethal or non-lethal force used by security guards.

“I’m not familiar with any data that spells out the nonfatal injuries caused by security guards,” he said.