National Institute of Justice National Institute of Justice. Research. Development. Evaluation. Office of Justice Programs
skip navigationHome  |  Help  |  Contact Us  |  Site Map   |  Glossary
Reliable Research. Real Results. skip navigation
skip navigation Additional Resources:

skip navigation

Program Profile

Operation Ceasefire (Boston, Mass.)

Evidence Rating: Effective - More than one study Effective - More than one study

Program Description

Program Goals/Target Population
Originally developed by the Boston (Mass.) Police Department’s Youth Violence Strike Force, Operation Ceasefire is a problem-solving police strategy that seeks to reduce gang violence, illegal gun possession, and gun violence in communities. The goals of the program are to carry out a comprehensive strategy to apprehend and prosecute offenders who carry firearms, to put others on notice that offenders face certain and serious punishment for carrying illegal firearms, and to prevent youths from following the same criminal path. As a deterrence strategy, the intervention is based on the assumption that crimes can be prevented when the costs of committing the crime are perceived by the offender to outweigh the benefits of committing a crime. It targets high-risk youths as well as serious and violent juvenile offenders.

The program is just one element of a collaborative, comprehensive strategy (which also includes the Boston Gun Project and Operation Night Light) implemented in Boston, Mass., to address escalating gang activity and rising violent crime rates. It combines aggressive law enforcement and prosecution efforts aimed at recovering illegal handguns, prosecuting dangerous felons, increasing public awareness, and promoting public safety and antiviolence.

Program Theory
The Operation Ceasefire intervention is a focused deterrence strategy. Deterrence theory posits that crimes can be prevented when the costs of committing the crime are perceived by the offender to outweigh the benefits of committing the crime (Braga et al. 2001). Operation Ceasefire used a pulling-levers approach, which attempted to prevent gang violence by making gang members believe that severe consequences would follow from violence and gun use, which would persuade them to change their behavior. A key element of the intervention was the delivery of a direct and explicit “retail deterrence” message to a relatively small target audience of gang members regarding what kind of behavior would provoke a special response and what that response would be. The deterrence message applied to a small audience (all gang-involved youths) rather than to a general audience (all youths in Boston). This way, the Ceasefire intervention would target those gangs who were engaged in violent behavior rather than expending resources on those who were not.

Program Components
The program’s suppression tactics include numerous warrants and long sentences for chronic offenders, aggressive enforcement of probation restrictions, and deployment of Federal enforcement powers. The prevention strategy is centered on an ambitious communications campaign involving meetings with both community groups and gang members. Everyone in the community is informed that gang violence will provoke a zero-tolerance approach and that only an end to gang violence will stop new gang-oriented suppression activities. Ideally, these activities should be combined with a variety of other law enforcement strategies and grassroots community initiatives to combat crime.

Operation Ceasefire’s first main element is a direct law-enforcement attack on illicit firearms traffickers who supply youths with guns. The program frames a set of activities intended to systematically address the patterns of firearm trafficking:

  • Expanding the attention of local, State, and Federal authorities to include intrastate trafficking in Massachusetts-sourced guns
  • Focusing enforcement attention on traffickers of those makes and calibers of guns used most often by gang members
  • Focusing enforcement attention on traffickers of those guns showing a short time to crime (18 months or less)
  • Focusing enforcement attention on traffickers of guns used by the city’s most violent gangs
  • Attempting to restore obliterated serial numbers
  • Supporting these practices through analysis of crime gun traces generated by the Boston Police Department's investigations and arrests involved with gangs or violent crimes
The second element, known as the “pulling levers” strategy, involves deterring violent behavior by chronic gang members by reaching out directly to gangs, saying explicitly that violence will not be tolerated, and by following every legally available route when violence occurs. Simultaneously, service providers, probation and parole officers, and church and other community groups offer gang members services and other kinds of help. The deterrence message was not a deal with gang members to stop violence. Rather, it was a guarantee to gang members that violent behavior would evoke an immediate and intense response. When gang violence did occur, Ceasefire agencies would address the violent group or groups involved, drawing from all possible legal levers. For instance, authorities could disrupt street drug activity, aim police attention toward low-level street crimes such as trespassing and public drinking, serve outstanding warrants, seize drug proceeds and other assets, request stronger bail terms (and enforce them), and turn potentially severe Federal investigative and prosecutorial attention toward gang-related drug activity. Because of the multitude of agencies involved in Operation Ceasefire, each gang who behaved violently could be subjected to such crackdowns. The operations could be customized to the particular individuals and characteristics of the gang in question.

Evaluation Outcomes

top border

Study 1

Youth Homicides

A simple pre/post comparison of time-series data conducted by Braga and colleagues (2001) found a statistically significant decrease in the monthly number of youth homicides in Boston, Mass., following implementation of Operation Ceasefire. There was a 63 percent reduction in the average monthly number of youth homicide victims, going from a pretest mean of 3.5 youth homicides per month to a posttest mean of 1.3 youth homicides per month. When control variables (such as Boston’s employment rate, and changes in citywide trends in violence) were added to the data analysis models to test whether other factors may have influenced or caused the reductions, the significant decrease in youth homicides associated with the Ceasefire intervention did not substantively change.


Citywide Gun Assaults

Ceasefire was associated with a 25 percent decrease in the monthly number of citywide gun assaults, and with a 44 percent decrease in the monthly number of youth gun assaults in district D–2. When control variables were added to the data analysis models, the significant reductions in gun assault incidents and youth gun assault incidents in District B–2 associated with Ceasefire did not change.


Calls for Service

The Ceasefire intervention was also associated with a 32 percent reduction in the monthly number of citywide shots-fired calls for service. When control variables were added to the data analysis models, the significant reduction in shots-fired calls for service associated with Ceasefire did not change.


Study 2

New Handguns Recovered Citywide

Braga and Pierce (2005) found that the Ceasefire intervention made a large impact on the yearly percentage of traceable handguns that were new with a fast time-to-crime (which is the time between a firearm’s first sale at retail and subsequent recovery in a crime) recovered by the Boston (Mass.) Police Department. Simple pre/post comparisons showed that the percentage of traced handguns with a fast time-to-crime increased steadily between 1991 and 1996, reaching a peak of 53.8 percent of traced handguns in 1996. Then between 1997 and 1999, the percentage of traced handguns with a fast time-to-crime decreased dramatically to 15.6 percent and remained at this lower level through 2003. Counting 1997 as the first full year of gun market intervention, there was a 47 percent reduction in the percentage of new traced handguns in Boston, from an average of 40.4 percent between 1991 and 1996 to an average of 21.4 percent between 1997 and 2003.


Multivariate analysis (which controlled for other predictor variables) of new handguns recovered in Boston found that Operation Ceasefire was associated with a statistically significant reduction in the percentage of recovered handguns that had a fast time-to-crime. Ceasefire was associated with a 22.7 percent reduction in the average monthly percentage of all recovered handguns that were new and a 24.3 percent reduction in the average monthly percentage of all recovered youth handguns that were new, as well as with a 29.7 percent reduction in the average monthly percentage of illegal possession handguns that were new and a 17.4 percent reduction in the average monthly percentage of all recovered substantive crime handguns that were new (all reductions were statistically significant).

bottom border

Evaluation Methodology

top border
Study 1
Braga and colleagues (2001) used a basic one-group time-series design to analyze the impact within Boston, Mass., associated with the Operation Ceasefire intervention. This method was used because there were no control areas within the city that could be set aside for comparison with treatment areas that would receive the intervention.

The primary outcome variable of interest in the study was the monthly number of homicide victims ages 24 and younger. Homicide data was provided by the Boston Police Department’s Office of Research and Analysis. The evaluation examined the monthly counts of homicides in Boston between Jan. 1, 1991, and May 31, 1998.

The evaluation also examined the monthly counts of citywide shots-fired citizen calls for service and citywide official gun assault incident reports. The data was examined from Jan. 1, 1991, through Dec. 31, 1997. The computerized Boston Police Department incident data did not capture the age of victims. As a result, information of the age of victims was collected from hard copies of gun assault incident reports for one high-activity police district. District B–2, which covered most of Boston’s Roxbury neighborhood and had a very dense concentration of gangs, was selected for examination.

In the analysis, May 15, 1996, was selected as the implementation date of the Ceasefire intervention. The preintervention time series was composed of the monthly counts between January 1991 and May 1996; the intervention time series was composed of monthly counts between June 1996 and May 1998 for homicide measures and between June 1996 and December 1997 for nonfatal serious violence indicators.

Generalized linear models were used in the analysis of the time-series data. Because the underlying data was counts, a Poisson regression in a log-linear model was selected to model the monthly counts. Control variables were added to the Poisson regression models to examine whether other causal factors may have caused or meaningfully influenced the youth homicide and gun violence rates.

The control variables included Boston’s employment rate measured by the Massachusetts Department of Employment and Training; changes in Boston’s youth population ages 5 to 24 as measured by the U.S. Bureau of Census; changes in citywide trends in violent crime as measured by the robbery data reported in the Federal Bureau of Investigation Uniform Crime Reports; changes in homicide victimization among older victims (ages 25 and older); and changes in youth involvement in street-level drug market activity as measured by Boston Police Department data.

Study 2
Braga and Pierce (2005) examined the impact of the Ceasefire gun market disruption strategy that was aimed at making an impact on the illegal trade in new handguns in all areas of Boston, Mass. The analysis also followed a basic one-group time-series design.

The effects of Operation Ceasefire’s supply-side intervention on new handguns recovered in Boston were analyzed based on four key outcome variables: 1) the monthly percentage of total handguns recovered that were new; 2) the monthly percentage of handguns recovered from youth that were new; 3) the monthly percentage of handguns recovered in illegal gun possession crimes that were new; and 4) the monthly percentage of handguns recovered in substantive crimes that were new.

Firearms trace data from the U.S. Bureau of Alcohol, Tobacco, and Firearms (ATF) were used to measure Ceasefire effects on the percentage of recovered handguns that were new in Boston over time. Manufacturers, importers, distributors, and Federal Firearms Licensees (FFLs) are required to maintain records of all firearms transactions, including sales and shipments received. FFLs must report multiple handgun sales and stolen firearms to ATF and provide transaction records to ATF in response to trace requests. In essence, a paper trail for gun transactions is created that can be followed by ATF agents.

However, there are limitations to trace data analyses. For instance, all are based on firearms recovered by police and other law enforcement agencies; however, this may not be representative of firearms possessed and used by criminals. Trace data sets are also influenced by which guns are submitted for tracing, which is a decision made by law enforcement agencies. Even when a trace is successful, it still provides limited information about the history of the gun. Trace studies typically contain information about the first retail sale and the circumstances surrounding the recovery by law enforcement, but studies cannot directly show what happened in between.

The preintervention time series was composed of monthly key outcome measures between January 1991 and May 1997, while the intervention time series was composed of the monthly measures between June 1997 and December 2003. The effects of Ceasefire were examined using ordinary least-squares linear regression models. Several control variables were included in the model to check for other factors that may confound the effects of Ceasefire. The control variables were the monthly number of violent gun crimes in Boston, the monthly number of handguns recovered in Boston, the monthly percentage of recovered handguns for which an age could not be determined, and a dummy variable indicating the passage of the Brady Handgun Violent Prevention Act implemented in February 1994.
bottom border


top border
There is no cost information available for this program.
bottom border

Implementation Information

top border
The National Network for Safe Communities, through the John Jay College of Criminal Justice, provides practitioners and researchers with information on Operation Ceasefire (also known as the group violence reduction strategy). The National Network Web site includes tools for practitioners such as basic and advanced implementation materials; reports and briefs highlighting particular components of the strategy; webinars and case studies; and related research. A link to the Web site is available under Additional References.
bottom border

Evidence-Base (Studies Reviewed)

top border
These sources were used in the development of the program profile:

Study 1
Braga, Anthony A., David M. Kennedy, Elin J. Waring, and Anne Morrison Piehl. 2001. “Problem-Oriented Policing, Deterrence, and Youth Violence: An Evaluation of Boston’s Operation Ceasefire.” Journal of Research in Crime and Delinquency 38(3):195–225.

Study 2
Braga, Anthony A., and Glenn L. Pierce. 2005. “Disrupting Illegal Firearms Markets in Boston: The Effects of Operation Ceasefire on the Supply of New Handguns to Criminals.” Criminology & Public Policy 4(4):717–48.
bottom border

Additional References

top border
These sources were used in the development of the program profile:

Braga, Anthony A., and David L. Weisburd. 2011. “The Effects of Focused Deterrence Strategies on Crime: A Systematic Review and Meta-Analysis of the Empirical Evidence.” Journal of Research in Crime and Delinquency:1–36.

Kennedy, David M., Anne Morrison Piehl, and Anthony A. Braga. 1996. “Youth Violence in Boston: Gun Markets, Serious Youth Offenders, and a Use-Reduction Strategy.” Law and Contemporary Problems 59(1):147–96.

Kennedy, David M., Anthony A. Braga, and Anne M. Piehl. 2001. “Reducing Gun Violence: The Boston Gun Project’s Operation Ceasefire.” Washington, D.C.: U.S. Department of Justice.

National Network for Safe Communities. 2012. “Group Violence Reduction Strategy.” New York, N.Y.: John Jay College of Criminal Justice, Center for Crime Prevention and Control.

Rosenfeld, Richard, Robert Fornango, and Eric Baumer. 2005. “Did Ceasefire, Compstat, and Exile Reduce Homicide?” Criminology & Public Policy 4(3):419–50. (This study was reviewed but did not meet criteria for inclusion in the overall program rating.)
bottom border

Related Practices

top border
Following are practices that are related to this program:

Focused Deterrence Strategies
Problem-oriented policing strategies that follow the core principles of deterrence theory.

Evidence Ratings for Outcomes:
Promising - One Meta-Analysis Crime & Delinquency - Multiple crime/offense types
bottom border

Program Snapshot

Age: 0 - 24

Gender: Both

Geography: Urban

Setting (Delivery): Other Community Setting, High Crime Neighborhoods/Hot Spots

Program Type: Community and Problem Oriented Policing, Community Awareness/Mobilization, Gang Prevention/Intervention, Children Exposed to Violence, Community Crime Prevention , Violence Prevention, Specific deterrence

Targeted Population: Serious/Violent Offender, Young Offenders, Children Exposed to Violence, Gang Members, High Risk Offenders

Current Program Status: Not Active

Listed by Other Directories: Child Exposure to Violence Evidence Based Guide, Campbell Collaboration, Model Programs Guide