Police Body Cams Are Making NYC Safer

In This Story

People Mentioned in This Story

In 2013, a federal judge ruled that the New York Police Department (NYPD)’s use of “Terry stops” – otherwise known as “stop-and-frisk” – violated the Fourth and Fourteenth Amendment of the U.S. Constitution. For years leading up to the decision, civil rights advocates pointed to the disproportionate number of stops to which African-Americans and Latinos in the city were subject as evidence of unfair targeting.

As per the judge’s orders, the NYPD underwent a one-year pilot program in which officers representing five precincts volunteered to wear body-worn cameras (BWC). This paved the way for a phased department-wide BWC rollout involving all 35,000 NYPD officers, starting in 2018.

BWC has been a controversial element within the broader debate about police violence in the U.S. The idea is to increase accountability and strict adherence to the law, for both the police and the public, by creating an objective record of every interaction. However, some argue that BWC recordings can be misleading. What the camera sees is not always the same as what the officer does. Theoretically, police who anticipate BWC footage may be deceptively used against them may reduce their interactions with the public when possible. If so, their reticence might put people at risk.

Making matters murkier, the research on BWC has mostly delivered mixed results. Some studies have shown arrests declining after BWC adoption; others have noted arrest increases; still others have found no change. The inconsistencies may be due to the specialized contexts and short duration of these studies – most dealt with small-scale trials in out-of-the-way places like Rialto, CA and Mesa, AZ.

School of Business Faculty Brad Greenwood
Brad Greenwood

For Brad Greenwood, a professor of information systems and operations management at the George Mason University School of Business, the NYPD – one of the world’s largest urban police forces – mandating BWC across the board on an indefinite basis was a research godsend. His forthcoming paper in Journal of Law, Economics & Organization (co-written by Mitchell E. Zamoff of University of Minnesota and Gordon Burtch of Boston University) is by far the most extensive analysis of BWC’s impact in a major American city.

The researchers combed through publicly available datasets detailing all NYPD stops, as well as arrest records and civilian complaint databases for the period January 2017-December 2019. The BWC rollout was complete by the end of 2018, so the three years covered by the study enabled the researchers to draw before-and-after comparisons for all 77 New York City police precincts.

The results of the study showed three clear patterns. First, fears that BWC would deter police from doing their job appeared unfounded. In fact, the number of investigative stops increased by nearly 17% after police were equipped with BWC.

Second, citizen complaints against police decreased by roughly 20% post-BWC, after accounting for the increase in stops. The category of complaint that saw the biggest decline was so-called “abuse of authority” – allegations of mistreatment or intimidation that may include improperly stopping, threatening, or seizing property from citizens. Of all the types of complaints investigated by NYC’s Citizen Complaint Review Board, abuse of authority is the most common.

Third, after adoption of BWC, the likelihood that a stop resulted in arrest went down by 16%.

Taken together, the findings indicate that, far from inhibiting police work, BWC emboldened police to undertake more investigative activity than they had before, without crossing the line into abuses of authority. Knowing they were being recorded also gave civilians an additional reason to be on their best behavior when stopped by the police – as perhaps reflected in the decline in arrests.

It isn’t clear from the data whether the change in outcomes was coming more from the officers’ side, from civilians, or a fairly even split. That is a question for future studies to resolve. Whatever the exact cause or causes, the study establishes that BWC had the intended beneficial effect in New York City.

That’s not to say that the program worked miracles, however. Citizen complaints alleging improper use of force, for example, did not decline but remained flat after accounting for the rise in stops.

Another caveat has to do with costs. By now, most large police departments in the U.S. have already adopted BWC. Smaller police departments with more modest budgets may have difficulty paying for cameras, training officers to use them properly and preserving vast archives of video evidence. They will have to decide whether the advantages of BWC outweigh the considerable costs for their town or city. By quantifying the positive effects of BWC, this study could enrich such cost-benefit analyses.

That’s the kind of contribution Greenwood intends to make with his research. He strives for data-driven insights that sidestep the ideological polarization that bogs down so many pertinent societal debates in the U.S. nowadays. “Objective and verifiable facts allow us to make decisions that are informed by data and improve outcomes for everyone”, Greenwood says. His research agenda is also evident in a study from earlier this year finding that black infant mortality rates were 50% lower when the doctor looking after the new-born was also black. Its data tells a sobering story about healthcare inequality that cries out for action without making ideologically loaded claims.

More broadly, Greenwood believes his NYPD findings also play into the hot-button issue of IT-enabled workplace surveillance. Here, too, there are complex trade-offs. Companies must weigh the prospect of pushback from employees who feel too closely watched against concerns about the bottom line and workforce accountability. The NYPD example may help organizations identify cases that may call for more monitoring rather than less – namely, where workers exercise a good deal of individual discretion, can push back against controls and may put themselves and/or others at risk in the course of their work.

Source: Mitchel E. Zamoff, Brad Greenwood, Gordon Burtch (2020). “Who Watches the Watchmen: Evidence of the Effect of Body-Worn Cameras on New York City Policing”