Deterring Gun Violence: Evidence from a Randomized Experiment in New York City
This study reports the first experimental evidence on an alternative approach often referred to as focused deterrence or “pulling levers,” a strategy that has substantial encouraging observational evidence behind it (Braga and Weisburd 2012). Focused deterrence programs are designed to deliver a message making clear that the consequences of future violations will be swift, severe, and certain, combining this message with enhanced enforcement for any violations committed by participants (especially crimes committed with a gun) (Papachristos et al. 2007). This message of deterrence is supplemented with a message of support from the community, and offers of assistance and social services to help participants succeed regarding housing, the labor market, family and community life (Braga & Kennedy, 2012). Conducted in an atmosphere designed to convey mutual respect and dignity, the model is intended to increase the legitimacy of the message delivered by representatives of law enforcement, social service providers, and community members (Tyler 2004).
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Although prior results from focused deterrence programs, including those from the Chicago PSN, provide suggestive evidence that these types of programs can be effective, little is known about the mechanisms by which the program works or the specific features of the program that are most important for program success. As discussed by Braga et al. (2019), the main theoretical effect of the forums is one of deterrence, by increasing the “certainty, swiftness, and severity” of punishment if an individual commits a future violent crime, increasing the salience of these punishments, and indirectly disseminating this information throughout the community. However, several additional mechanisms have been proposed, including redirecting individuals away from crime by providing access to social services and community supports (Braga et al., 2008), increasing the collective efficacy of a community (Sampson et al., 1997), and improving perceptions of the legitimacy of the procedural justice system (Nagan and Telep, 2017).3
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Another hypothesis is that the null effect we observed was due to selecting parolees as the population of interest. Thought the Chicago PSN found positive effects of the program for this population, it is possible that focused deterrence notification forums are less effective for individuals recently released from prison than for other high-risk individuals who live in the community. Paroled individuals interact with the procedural justice system on a day-to-day basis, have interacted with the system constantly while incarcerated over the past several years, and thus may already have a strong understanding of the swift, certain, and severe punishments they will receive if they are arrested for future violent crimes. As such, these notification forums may do relatively little to increase the already substantial awareness of parolees about potential future sanctions or change their perceptions of the legitimacy of the procedural justice system.
