Scholars in the field of public health have become increasingly influential in asserting their conceptualization of gun violence prevention, and the attendant research priorities. Of course gun violence is inescapably a public health problem, with nearly 40,000 killed each year (almost as many as in traffic accidents).1Sherry L. Murphy et al., “Deaths: Final Data for 2015,” National Vital Statistics Reports 66, no. 6 (2017): 1–73. Compared to the usual focus of discussions on gun control and the criminal justice system, which emphasize criminal assault and homicide, the public health perspective broadens the discussion to victimization of all sorts, including suicide and accidents. (Indeed, criminal acts only account for about 37 percent of gun deaths.) Public health endorses a comprehensive, nonjudgmental, pragmatic, evidence-based approach to saving lives and reducing injury, with a strong emphasis on prevention.2David Hemenway and Matthew Miller, “Public Health Approach to the Prevention of Gun Violence,” New England Journal of Medicine 368, no. 21 (2013): 2033–5. Also see Mark H. Moore, “Violence Prevention: Criminal Justice or Public Health?Health Affairs 12, no. 4 (1993): 34–45. All good, but there is something important missing. In practice, when it comes to prevention of criminal misuse of guns, public health scholars tend to ignore or minimize what we argue is the most important targeted prevention capacity: the criminal justice system’s ability to arrest, punish, and incapacitate shooters.

“The de facto impunity for shooters in Chicago surely helps explain Chicago’s high rate of gun violence as it undermines both the deterrent and incapacitation effects of the system, and potentially fuels a cycle of private retaliation.”

The potential importance of this capacity is most intuitively evident when it fails. Consider the weekend of August 4 in Chicago in which a total of 74 people were shot (including a stretch with 30 shot over three hours). Just one of the shooters was arrested. One arrest out of 74 is even worse than normal—on average, about 5 percent of shooters are arrested in nonfatal cases and 17 percent if the victim dies.3Chicago: The University of Chicago Crime Lab, 2017More Info → Even when there is an arrest, a conviction is far from guaranteed. The de facto impunity for shooters in Chicago surely helps explain Chicago’s high rate of gun violence as it undermines both the deterrent and incapacitation effects of the system, and potentially fuels a cycle of private retaliation.

In what follows we argue that the valuable efforts to prevent gun violence through gun regulation, conflict mediation, and preventive police patrols should not be viewed as a replacement for effective police investigations intended to hold shooters accountable. As in other cities burdened by gun violence, Chicago authorities acknowledge the desirability of increasing clearance rates in shootings. But what are the promising, evidence-based reforms that would help accomplish this important purpose? The sad fact is that there is little in the way of useful guidance from systematic research.

Our argument in support of more research in this area rests on two claims. First, criminal investigations are complex enterprises that could quite possibly be made more efficient and effective through systematic analysis. And second, if successful, the resulting increase in the likelihood of arrest, conviction, and punishment for criminal assault or homicide with a gun would reduce the volume of gun violence. In a nutshell, effective police work is a vital complement to other efforts (including those touted within the public health framework) to develop an effective gun violence prevention program.

The paucity of research on police investigations and gun violence

David Hemenway and Matthew Miller list five key components of the public health approach, including the focus on prevention—“usually as far upstream as possible”—and an emphasis on “shared responsibility over blame.”4Hemenway and Miller, “Public Health Approach to the Prevention of Gun Violence,” 2033–5. They state that the criminal justice system “plays a crucial role,” but then go on to say that “public health particularly applauds innovative policing that works with the community to help prevent violence.” There is nothing in this essay about the importance of clearing serious assault and homicide cases.

Following the Sandy Hook massacre, President Obama tasked the Centers for Disease Control and Prevention (CDC) to develop a research agenda on gun violence prevention. The CDC turned to the Institute of Medicine to assemble an expert panel with the task of providing a comprehensive plan. The resulting document, Priorities for Research to Reduce the Threat of Firearm-Related Violence, covers a lot of territory, but does not even mention increasing arrest rates for criminal shootings.5Washington DC: National Academies Press, 2013More Info →

This push for prevention within public health has occurred alongside a similar re-orientation over time within the policing profession itself.6New York: Spiegel & Grau, 2015More Info → The police have long had the lead responsibility for investigating serious crimes, arresting suspected perpetrators, and making a case against them that would stand up in court. This set of responsibilities falls under the rubric of “reactive” policing (along with responding to 911 calls). In the last 30 years or so, criminologists and opinion leaders have been skeptical that much is accomplished by reactive policing.7→Malcolm Sparrow, Mark H. Moore, and David M. Kennedy, Beyond 911: A New Era for Policing (New York: Basic Books, 1990).
→Wesley Skogan and Kathleen Frydl, eds., Fairness and Effectiveness in Policing: The Evidence (Washington DC: The National Academies Press, 2004), Chap. 6.
→Anthony A. Braga, Brandon Turchan, and Lisa Barao, “The Influence of Investigative Resources on Homicide Clearances,” Journal of Quantitative Criminology 2018: 1–28.
Police chiefs have learned to espouse proactive measures, such as intensive patrol of crime hot spots, problem-oriented policing, and perhaps some version of zero-tolerance policing inspired by the broken windows metaphor.8→Stephen D. Mastrofski, “Ideas & Insights: Police CEOs: Agents of Change?Police Chief 82 (November 2015): 53–54.
→David Weisburd and Malay Majmundar, eds., Proactive Policing: Effects on Crime and Communities (Washington, DC: The National Academies Press, 2018).
Community policing has also acquired considerable cachet.9Washington, DC: Brookings Institution Press, 2016More Info → In this new prevention-oriented ethos, crime investigation seems old fashioned. But in our view, reactive policing is a vital component of preventing gun violence, and is ignored at our peril.

The role of police investigation in gun violence prevention

“Criminologists have identified the two principal mechanisms by which reactive policing can prevent crime as deterrence and incapacitation.”

Sir Robert Peel, the father of British policing (hence the nickname “bobbies”) is credited with nine principles formulated in 1829 to guide the new police force. His first principle: “The basic mission for which the police exist is to prevent crime and disorder.” Criminologists have identified the two principal mechanisms by which reactive policing can prevent crime as deterrence and incapacitation. Some individuals may be deterred from shooting another during a robbery, gang beef, or domestic argument by the perceived threat of arrest and punishment. If shooters are routinely convicted and imprisoned, that threat will have reality and be transmitted more effectively to the relevant individuals (members of violent gangs and the like). A modern variant on reactive policing utilizes focused deterrence, where the police address groups of gang members personally, warning them that they are being watched and will suffer legal consequences if they are suspected of misusing guns—but presumably that approach also requires that the police and courts make good on the threat if it is tested.10Weisburd and Majmundar, Proactive Policing.

The other principal mechanism, incapacitation, requires convicts be punished by imprisonment or some other method that limits their freedom. There is fairly good evidence on the careers of violent criminals, suggesting that those who commit a serious crime with a gun are at high risk for doing so again if left at large, and that this active period may be naturally limited to a few years.11See, for example, David Kennedy, Anne Piehl, and Anthony Braga, “Youth Violence in Boston: Gun Markets, Serious Youth Offenders, and a Use-Reduction Strategy,” Law and Contemporary Problems 59, no. 1 (1996): 147–196. If a portion of those high-violence years are spent in prison, the result is less violent crime in the community.

There are other mechanisms that plausibly link the success rates of police investigations to gun crime. They are difficult to quantify, but may nonetheless be of some importance. First is the extent that the police are viewed as effective, which reduces the motivation for retaliation by survivors and their associates. The criminal justice system is intended to preempt private vigilante action, but that purpose is undercut by poor performance. Arresting less than 10 percent of shooters (as is currently the case in Chicago) may not assuage the instinct of survivors, their families, and their gangs to avenge their victimization.

Second, and closely related, is the relationship between the police and the community. The police require the cooperation of the community to be effective in solving crimes, but it is arguably a two-way street. If the relevant community believes police are indifferent to crimes involving minority youths as victims, as indicated by the routine failure of investigations, then the police may be viewed with still more suspicion and distrust.

Promising research areas

For starters, it would be useful to understand more about the optimal allocation of police resources to prevention versus investigation. The size of the Chicago Police Department’s detective force has dwindled substantially in the last decade. As a result, the share of sworn officers who are detectives is about half as high in Chicago as in other large cities that have much lower homicide rates, like Los Angeles and New York (8 percent versus 15 percent). Whether Chicago has actually made a mistake requires a better understanding of the marginal crime-control benefit of allocating an additional officer to detective versus other duties.

“Very little scientifically credible evidence is currently available, for instance, about what sorts of professional development or training helps make detectives better at clearing cases.”

Also important would be to understand whether it is possible to improve the effectiveness or efficiency of existing investigative capacity. Very little scientifically credible evidence is currently available, for instance, about what sorts of professional development or training helps make detectives better at clearing cases. Surely there are also numerous other organizational processes that wind up being bottlenecks that impede successful investigation.12Anthony A. Braga and Desiree Dusseault, “Can Homicide Detectives Improve Homicide Clearance Rates?Crime and Delinquency 64, no. 3 (2016): 283–315. A growing body of research within economics reveals that even private-sector companies with strong profit motives to operate as effectively as possible often have room for management improvements; it seems hard to believe the same would not be true for local government bureaucracies like detective bureaus.

A third key priority area is to improve witness cooperation. Partly this must be about strengthening police-community relations, although how police might effectively “win hearts and minds” remains poorly understood. Public attitudes regarding police are influenced by current police behavior, but perhaps also due in part to the history of policing in America (such as enforcement of then-legal segregation). Helping keep witnesses safe in dangerous neighborhoods that are often essentially run by street gangs is another key challenge; for example, a recent proposal in Chicago is to greatly expand witness protection programs, although whether that is actually a good use of resources is currently unknown.

These represent some of the most important priorities, in our view, for research in this area, but are nowhere near an exhaustive list. Criminologists, public health scholars, and other researchers who focus on gun violence prevention have largely ignored the challenge of improving clearance rates. This is an unfortunate omission that should be remedied as new research agendas on gun violence are developed.

References:

1
Sherry L. Murphy et al., “Deaths: Final Data for 2015,” National Vital Statistics Reports 66, no. 6 (2017): 1–73.
2
David Hemenway and Matthew Miller, “Public Health Approach to the Prevention of Gun Violence,” New England Journal of Medicine 368, no. 21 (2013): 2033–5. Also see Mark H. Moore, “Violence Prevention: Criminal Justice or Public Health?Health Affairs 12, no. 4 (1993): 34–45.
3
Chicago: The University of Chicago Crime Lab, 2017More Info →
4
Hemenway and Miller, “Public Health Approach to the Prevention of Gun Violence,” 2033–5.
5
Washington DC: National Academies Press, 2013More Info →
6
New York: Spiegel & Grau, 2015More Info →
7
→Malcolm Sparrow, Mark H. Moore, and David M. Kennedy, Beyond 911: A New Era for Policing (New York: Basic Books, 1990).
→Wesley Skogan and Kathleen Frydl, eds., Fairness and Effectiveness in Policing: The Evidence (Washington DC: The National Academies Press, 2004), Chap. 6.
→Anthony A. Braga, Brandon Turchan, and Lisa Barao, “The Influence of Investigative Resources on Homicide Clearances,” Journal of Quantitative Criminology 2018: 1–28.
8
→Stephen D. Mastrofski, “Ideas & Insights: Police CEOs: Agents of Change?Police Chief 82 (November 2015): 53–54.
→David Weisburd and Malay Majmundar, eds., Proactive Policing: Effects on Crime and Communities (Washington, DC: The National Academies Press, 2018).
9
Washington, DC: Brookings Institution Press, 2016More Info →
10
Weisburd and Majmundar, Proactive Policing.
11
See, for example, David Kennedy, Anne Piehl, and Anthony Braga, “Youth Violence in Boston: Gun Markets, Serious Youth Offenders, and a Use-Reduction Strategy,” Law and Contemporary Problems 59, no. 1 (1996): 147–196.
12
Anthony A. Braga and Desiree Dusseault, “Can Homicide Detectives Improve Homicide Clearance Rates?Crime and Delinquency 64, no. 3 (2016): 283–315.