Evidence on Measures to Reduce Excessive Use of Force by the Police

The tragic killings of a number of unarmed Black individuals by law enforcement officers, including Tamir Rice, George Floyd, Philando Castile and Breonna Taylor, has brought the racialized nature of law enforcement to the forefront of reform efforts. Americans of every race and ethnicity are at risk of police violence. More White Americans are killed by police than people of color each year. However, Black Americans, in particular, are disproportionately at risk. Police are more likely to stop Black Americans than White Americans, to use higher levels of force with Black Americans than White Americans, and to kill Black Americans than White Americans. With approximately 1,000 individuals killed by police every year in the United States, the rate at which civilians die by the hand of law enforcement is extremely high compared to other democracies. Indeed, an analysis by the Guardian comparing police shootings across several countries found that U.S. police kill more people in days than other countries do in years. Yet how best to turn the tide on this national challenge remains unclear. Due to inconsistent data and reporting practices, as well as limited research, there is actually little empirical evidence to tell us which of the commonly advocated reforms are effective at reducing police use of force rates. The goal of this report is to look at a number of the reforms currently being discussed and/or implemented across the country and identify the empirical evidence regarding their effectiveness.

Key findings

• Limited Evidence on Use of Force Policies: A variety of policies seek to reduce police use of force but limited data, a lack of transparency with existing data, inconsistencies in measurement and definitions, and irregular implementation contribute to the lack of clarity about the impact of these policies. There is a clear need for more data as well as research that can measure the causal effect of narrowly defined policies.
• Black and Women Officers are Less Likely to Use Force: Black officers (and to a lesser degree, Latino officers) are significantly less likely to stop, arrest, and use force against civilians, especially Black civilians, relative to White officers. Women officers are also significantly less likely to arrest and use force against civilians, and especially against Black civilians, relative to men.
• Gun Control Policies Matter: Of all of the policies considered, stricter firearm policies had the most consistent relationship with reduced use of force among police. Additionally, the fact that many states and localities have relatively lenient gun control policies makes this an area with particularly strong potential for impact on police use of force rates.
• Evidence on Body Worn Cameras Suggest Positive Impact: While early research on the impact of body worn cameras pointed to an inconsistent relationship with police use of force, new evidence strongly suggests that these policies can reduce police use of force and civilian complaints when worn by officers who do not have discretion over when the cameras are turned on and off.