Criminal Justice Interventions

Policing and sentencing interventions have had recent broad bipartisan

support and are a major focus of current efforts to reduce firearms violence.

These policies generally do not affect the ability of law-abiding citizens to

keep guns for recreation or self-defense, and they have the potential to

reduce gun violence by deterring or incapacitating violent offenders. Descriptive

accounts suggest that some of these policies may have had dramatic

crime-reducing effects: homicide rates fell dramatically after the implementation

of Boston’s targeted policing program, Operation Ceasefire, and

Richmond’s sentencing enhancement program, Project Exile.

Despite these apparent associations between crime and policing policy,

however, the available research evidence on the effects of policing and

sentencing enhancements on firearm crime is limited and mixed. Some

sentencing enhancement policies appear to have modest crime-reducing

effects, while the effects of others appear to be negligible. The limited

evidence on Project Exile suggests that it has had almost no effect on

homicide. Several city-based quasi-random interventions provide favorable

evidence on the effectiveness of targeted place-based gun and crime suppression

patrols, but this evidence is both application-specific and difficult

to disentangle. Evidence on Operation Ceasefire, perhaps the most frequently

cited of all targeted policing efforts to reduce firearms violence, is

limited by the fact that it is a single case at a specific time and location.

Scientific support for the effectiveness of the Boston Gun Project and most

other similar types of targeted policing programs is still evolving.

The lack of research on these potentially important kinds of policies is

an important shortcoming in the body of knowledge on firearms injury

interventions. These programs are widely viewed as effective, but in fact

knowledge of whether and how they reduce crime is limited. Without a

stronger research base, policy makers considering adoption of similar programs

in other settings must make decisions without knowing the true

benefits and costs of these policing and sentencing interventions.

The committee recommends that a sustained, systematic research program

be conducted to assess the effect of targeted policing and sentencing

aimed at firearms offenders. Additional insights may be gained from using

observational data from different applications, especially if combined with

more thoughtful behavioral models of policing and crime. City-level studies

on the effect of sentencing enhancement policies need to engage more rigorous

methods, such as pooled time-series cross-sectional studies that allow

the detection of short-term impacts while controlling for variation in violence

levels across different areas as well as different times. Another important

means of assessing the impact of these types of targeted policing and

sentencing interventions would be to conduct randomized experiments to

disentangle the effects of the various levers, as well as to more generally

assess the effectiveness of these targeted policing programs.