• Group Violence Intervention

    The Group Violence Intervention (GVI) reduces violent crime when community members join together with law enforcement and social service providers to focus an antiviolence message on highly active street groups.

About the Strategy
Tools & Guides

The Group Violence Intervention (GVI) is designed to reduce street group-involved homicide and gun violence. Pioneered by National Network Director David Kennedy and colleagues as “Operation Ceasefire” in Boston during the 1990s, it has been implemented widely nationally, including currently in the very challenging cities of Chicago, New Orleans, Oakland, and Baltimore, and has acquired a strong formal evaluation record, as presented in the gold-standard Campbell Collaboration Systematic Review.

GVI has repeatedly demonstrated that violence can be dramatically reduced when a partnership of community members, law enforcement, and social service providers directly engages with the small and active number of people involved in street groups and clearly communicates a credible moral message against violence, prior notice about the consequences of further violence, and a genuine offer of help for those who want it. A central method of communication is the call-in, a face-to-face meeting between group members and the strategy’s partners.

The aim of the GVI strategy is to reduce peer dynamics in the group that promote violence by creating collective accountability, to foster internal social pressure that deters violence, to establish clear community standards against violence, to offer group members an “honorable exit” from committing acts of violence, and to provide a supported path for those who want to change.

The National Network produced Group Violence Intervention: An Implementation Guide, published by COPS Office in 2013, to provide a practical tool for stakeholders seeking to implement GVI in their jurisdiction.

Group Violence Intervention: An Implementation Guide

A comprehensive guide to the National Network's Group Violence Intervention strategy. This guide covers all relevant steps to the strategy from initial planning and problem analysis to enforcement actions and call-in implementation, and further considers issues of maintenance, integrity, sustainability and accountability to offer interested parties a step-by-step guide to successfully implementing GVI in any jurisdiction.

GVI: A Guide for Project Managers

This guide is a high-level overview of the role of the Project Manager in the Group Violence Intervention. It outlines the key operational components of a successful GVI implementation and provides strategic insights from current and previous GVI Project Managers. 

Custom Notifications: Individualized Communication in the Group Violence Intervention

This guide provides practical information about "custom notifications," an independent element of GVI that enables quick, tactical, direct communication to particular group members. This publication presents the custom notifications process, explains its value within the broader strategy, details its use by several national practitioners, and encourages further development.

Managing the Group Violence Intervention: Using Shooting Scorecards to Track Group Violence

This guide begins with a brief description of the shooting scorecard concept and its links to problem analysis and performance measurement systems in police departments. It then presents the key steps in the process and associated data quality issues and then details the use of shooting scorecards by the Boston Police Department as an example of the practical applications of this approach.

Call-In Preparation and Execution Guide

A complete guide for law enforcement, community, and social services partners already engaged in implementing the Group Violence Intervention to design, prepare, and execute their first and subsequent call-ins.

User Manual: Network Analysis and Visualization for Crime Prevention (NAVCAP)

NAVCAP offers practitioners the ability to map and analyze individual co-offending networks and group relationship networks without the need for coding or command line experience. This manual describes the installation, capabilities, and use of NAVCAP, using four educational modules. 

Four Case Studies of Swift and Meaningful Law Enforcement

For the Group Violence Intervention to achieve its desired outcomes, stakeholders must be authentic and their messages credible. For law enforcement this means making good on the promise of swift and meaningful consequences for a group or gang as a whole when a prohibited violent act (usually shooting or killing) is committed by one of its members. This document captures examples of successful and creative law enforcement responses to group violence as carried out by police departments and their partner agencies in key National Network jurisdictions.

Pulling Levers Focused Deterrence Strategies to Prevent Crime

This paper briefly reviews the research on the crime control effectiveness of "pulling levers" focused deterrence programs. Focused deterrence strategies honor core deterrence ideas, such as increasing risks faced by offenders, while finding new and creative ways of deploying traditional and non-traditional law enforcement tools to do so, such as communicating incentives and disincentives directly to targeted offenders.

The Effects of “Pulling Levers” Focused Deterrence Strategies on Crime

This report is a meta-analysis that evaluates impact on homicide and violence in a variety of cities that have implemented our Group Violence Intervention or the Drug Market Intervention.

Philadelphia Focused Deterrence Call-in (May 16, 2013)

This is a May 16, 2013 "call-in" meeting of the Philadelphia Focused Deterrence initiative, at which Philadelphia community members, law enforcement, and social service providers join together and use the National Network for Safe Communities' method of communicating directly with active gang and street group members.


Baton Rouge BRAVE Call-in (September 23, 2014)

This is a September 23, 2014 "call-in" meeting of the Baton Rouge Area Violence Elimination (BRAVE) initiative, at which Baton Rouge community members, law enforcement, and social service providers join together and use the National Network for Safe Communities' method of communicating directly with active gang and street group members.

Developing a Step-by-Step Application of the New Orleans Strategy to Combat Violent Street Crews In a Focused Deterrence Strategy

In this brief, K. Tate Chambers outlines a step-by-step application of the New Orleans Strategy to combat violent street crews and how it was employed in Don't Shoot Peoria's focused deterrence crime prevention plan. This article outlines the 14 steps used by Don't Shoot Peoria to implement the focused deterrence strategy and also explains some of the practical applications of these steps. 

Webinar: Employing Streetworkers to Address Group Violence (2011)

The Institute of the Study & Practice of Nonviolence in Providence is a national pioneer in training and employing professional street outreach workers to address and prevent violence. It has also forged a highly effective partnership with the Providence Police Department that the National Network for Safe Communities believes can serve as a model for other jurisdictions seeking to utilize street outreach workers as part of implementing the Group Violence Intervention. In this webinar, the Institute’s Executive Director Teny Gross and Streetworker Program Manager Ajay Benton discuss the following key issues: Principles and Practice of Nonviolence; Training; Hiring & Firing; Partnering With Police, Schools, and Hospitals; Selecting Target Clients; Managing Risks; Managing Public Relations; Measuring Success. Click here for the webinar's PowerPoint.

Webinar: Communicating with Offenders—Innovative Notification Strategies (2010)

This webinar focuses on innovative techniques for communicating key messages to offenders, potential offenders and affected communities as part of the National Network's group violence reduction and drug market strategies. Key issues include: Best practices in the "classic" call-in format; Voluntary call-ins for gang members; Home visits with impact players; Custom legal assessments; Prison call-ins; The use of "influentials" in both strategies; Emphasizing legitimacy in the call-in; Use of social network analysis. 

Chicago Violence Reduction Strategy: Applications of Social Network Analysis (2011)

Social network analysis is an integral part of Chicago's Violence Reduction Strategy (VRS). It is used to expand and improve the police department's intelligence on gangs, groups and local gang factions; to identify the most socially connected group and gang members to take the VRS anti-violence message back to their associates; and to assess the impact of law enforcement efforts on groups or gangs. This document outlines three examples of social network analysis as a tool to narrowly and effectively focus law enforcement resources on group violence.

Webinar: Using Social Network Analysis in Crime Prevention (2011)

Social network analysis— the scientific tool behind social media like Facebook and Twitter—is used widely in the private sector to understand markets and organizations and in the health sector to understand the spread of disease. It can be used just as effectively to devise new ways to reduce violent crime. Leadership Group jurisdictions Chicago and Cincinnati have been at the forefront of applying social network analysis in crime prevention. In this webinar, Andrew Papachristos, Ph.D., a national expert and the research partner of the Chicago Police Department, and Captain Daniel Gerard of the Cincinnati Police Department will demonstrate how social network analysis is applied in the context of the Group Violence Intervention. Key issues addressed include: Mapping of group, gang and faction structures and relationships; designing surgically precise enforcement actions; expanding knowledge of group membership using commonly available administrative data; identifying the most influential group members for taking antiviolence messages back to affiliates. Click here for the webinar's PowerPoint.

Cincinnati Initiative to Reduce Violence: Home/Street Visits (2011)

A report about the groundbreaking home/street visits approach developed by the Cincinnati Initiative to Reduce Violence (CIRV) to keep its anti-violence message "fresh" in between its formal court house call-ins. The CIRV team identifies key impact players within groups active in crime hot-spots, meets with them face-to-face at their homes or in the streets, and delivers the message in a way that has led to substantial reductions in shootings around the city.

Practice Brief: Group Enforcement Actions and Talking Points (2010)

This brief explores the role and purpose of demonstration, and subsequent, group enforcement actions ("crackdowns") associated with the law enforcement component of the Group Violence Intervention, including talking points for presenting these actions within actual call-ins/notification meetings with group and gang members.

Integrating and Evaluating Multiple PSN Strategies in Chicago (2009)

This PowerPoint presentation summarizes findings from an evaluation of the impact of Project Safe Neighborhood (PSN) initiatives on neighborhood level crime rates in Chicago. Several PSN interventions were found to be associated with greater declines of homicide in the treatment neighborhoods compared to the control neighborhoods. Out of four interventions analyzed, the largest effect was associated with the offender notifications that stress individual deterrence, normative change in offender behavior, and increasing views on legitimacy and procedural justice.

Building Collaborative Violent Crime Task Force Structures (2009)

This PowerPoint presentation, by Robert A.J. Lang, Assistant U.S. Attorney for the Middle District of North Carolina, and Jodi A. Ramirez, Law Enforcement Coordinator/Program Manager of Project Safe Cabarrus, sets out how to create the partnerships and agency structures necessary to successfully implement and sustain the group violence strategy. It includes guidelines on how best to overcome common institutional barriers as well as best practices for sustaining the initiative.

Cincinnati Initiative to Reduce Violence (CIRV) – Organizational Structure, Processes and Outcomes (2009)

This PowerPoint presentation, by CIRV Executive Director Greg Baker, provides an outline of the structure, processes and outcomes of the initiative, aimed at reducing gun violence and homicides in Cincinnati.

Project Safe Cabarraus – Program Manager Position (2009)

The document provides a description of the Project Manager position in this initiative. The Project Manager is responsible for coordinating community-wide resources, agencies, and committees as part of the federally funded Project Safe Neighborhood (PSN) initiative. PSN is based in part on the National Network's group violence strategy.

Controlling Gang Violence in High Point – High Point Police Department (2008)

This PowerPoint presentation by the High Point Police Department includes an outline of the theory underlying the group violence strategy, a step-by-step implementation guide, a link analysis of the groups engaged in violent crime in High Point, and details of the department's organizational realignment to more effectively support its mission of crime reduction.

Hot People, Hot Places: Two Frameworks for Modern Strategic Crime Control

This PowerPoint presentation was developed by David Kennedy for the National Organization of Black Law Enforcement Executives 2016 William R. Bracey Symposium in Hollywood, FL on February 12, 2015.

Braga, A., Weisburd, D. L. (2012). The Effects of “Pulling Levers” Focused Deterrence Strategies on Crime. Campbell Systematic Reviews. DOI: 10.4073/csr.2012.6

Braga, A. A., Weisburd, D.L. (2012). Pulling Levers Focused Deterrence Strategies to Prevent Crime. No. 6 of Crime Prevention Research Review. Washington, D.C.: U.S. Department of Justice, Office of Community Oriented Policing Services.

Braga, A. A., Hureau, D., & Winship, C. (2008). Losing Faith? Police, Black Churches, and the Resurgence of Youth Violence in Boston. Ohio State Journal of Criminal Law, 6 (1) 141-172

Braga, A. A., McDevitt, J., & Pierce, G. L. (2006). Understanding and Preventing Gang Violence: Problem Analysis and Response Development in Lowell, Massachusetts. Police Quarterly, 9 (1) 20-46

Braga, A A., Kennedy, D.M., Piehl, A.M., & Waring, E.J. (2001, September). Reducing Gun Violence: The Boston Gun Project’s Operation Ceasefire. National Institute of Justice Research Report

Corsaro, N., & Engel, R. S. (2015). Most Challenging of Contexts: Assessing the Impact of Focused Deterrence on Serious Violence in New OrleansCriminology & Public Policy, 14(3). DOI:10.1111/1745-9133.12142.

Kennedy, D.M. (2008). Deterrence and Crime Prevention: Reconsidering the Prospect of Sanction. NY: Routledge.

Mazerolle, L., Bennett, S., Davis, J., Sargeant, E., Manning, M. (2012) Legitmacy in Policing. Campbell Systematic Reviews.

Meares, T. L.(2009). The Legitimacy of Police Among Young African-American Men. Faculty Scholarship Series. Paper 528.

McGarrell, E., & Chermak, S. (2003, October). Strategic Approaches to Reducing Firearms Violence: Final Report on the Indianapolis Violence Reduction Partnership. National Criminal Justice Reference Service.

Papachristos, A. V., & Kirk, D. S. (2015). Changing the Street Dynamic: Evaluating Chicago’s Group Violence Reduction StrategyCriminology & Public Policy, 14(3). DOI:10.1111/1745-9133.12142.

Papachristos, A. V., Meares, T., & Fagan, J. (2007). Attention Felons: Evaluating Project Safe Neighborhoods in Chicago. Journal of Empirical Legal Studies, 4 (2) 223-272.



reduction in gun homicide through Stockton Operation Peacekeeper, 1997-2002



reduction in group member-involved homicide



reduction in overall shooting behavior among factions represented at call-ins



reduction in victimization among factions represented at call-ins



reduction in gang-involved shootings among gangs treated with crackdowns



reduction in shootings among notified violent groups



reduction in gun assaults through Project Safe Neighborhooods



decrease in group member-involved homicides

New Orleans


reduction in youth homicide



reduction in homicide


News & Updates

Helfrich optimistic about York’s gun-violence initiative

February 2018  |  York Dispatch  

Helfrich said York City residents need to understand that GVI isn't a short-term program. It's how the city will be doing business from now on. "We will be wherever the violence is," Helfrich said. "We will be there with all the services we can provide — and all the enforcement we can provide. Our mission hasn't changed." 


Tags: York Group Violence Intervention Support and Outreach

Focused Deterrence Strategies Save Lives

January 2018  |  Criminology & Public Policy  

An important new meta-analysis of 24 focused deterrence implementations—in particular, the National Network’s Group Violence Intervention and Drug Market Intervention—was published in Criminology & Public Policy. The systematic review, led by Professors Weisburd, Braga, and Turchan, found that focused deterrence strategies “generate noteworthy crime reduction impacts and should be part of a broader portfolio of crime reduction strategies available to policy makers and practitioners.”

In a companion paper analyzing the findings of the systematic review, Professor Robin Engel put a finer tip on their conclusion: "Focused deterrence strategies save lives." 

Tags: Drug Market InterventionGroup Violence Intervention

Authorities in Malmö: Stop shooting

January 2018  |  Sverige Radio  

"The special thing is that several government agencies work together and that they have the same message and that is: stop shooting," says Anna von Reis, Head of Department of Social Work and Social Affairs in Malmö.

Of the 200 Malmö criminal networks, they have issued those who either have a conditional sentence or are under supervision and therefore may be forced to a meeting where, among other things, the social service explains what they can assist.

Tags: Group Violence Intervention

Newburgh crime rates lowest ‘in over 10 years’

January 2018  |  Times Herald-Record  

Violent crime in Newburgh continued to fall last year as the city waits for the state to determine if former Beacon police Chief Doug Solomon is eligible to lead its department, City Manager Michael Ciaravino said on Monday.

The combined number of aggravated assaults, homicides, rapes and robberies in 2017 fell by 14 percent from 2016, Ciaravino told the City Council. Part 1 crimes, which include violent crimes along with arson, burglaries, car thefts and larcenies, were down almost 15 percent, he said.

There were six homicides last year, the same as in 2016, but the overall number of people injured by gunshots dropped significantly last year, from 48 to 17, Ciaravino said.

“This was the lowest crime rates in over 10 years,” he said.

Tags: Newburgh Group Violence Intervention

‘Peace Builders’ to tackle violence in Bermuda

January 2018  |  The Royal Gazette  

Training is to be given to “everyday men and women” who want to help tackle gang violence and antisocial behaviour, it was revealed yesterday.

Wayne Caines, Minister of National Security, said more than 100 people had expressed an interest in the new Peace Builders programme, which will cover topics that include mental health, disaster management and what to do in a crisis.

Mr Caines said: “The aim is to deploy a cadre of citizens to support neighbourhoods, to reduce tensions in recognised hotspots and to provide a reassuring presence in the event of a crisis.

Tags: Group Violence Intervention

Jacksonville death toll troubling, but officials say there is hope

January 2018  |  The Florida Times-Union  

Murders, where someone illegally takes the life of someone, are different from homicides, which can include justifiable self-defense shootings, Sheriff Mike Williams said. So his agency’s cumulative numbers were a bit lower for 2017. But each one was “a tragedy,” Williams said, as he reiterated that many stem from a small percent of the city’s population made up of gang members, entertainment groups, drug crews and that street culture. And it’s been that way for the last few years.

“We know we have a relatively small number of people that are driving a significant portion of the violence,” Williams said. “When I say driving the violence, it is not that this number of people are victimizing the community over and over. They are victimizing themselves. When I say themselves, I am talking about the community of people who buy, sell and use drugs and hang around people who do. ... That is the group victimizing themselves over and over again, which in every city drives up murder and violent crime rates.”

Tags: Jacksonville Group Violence Intervention

Detroit has lowest homicide tally in 50 years

January 2018  |  The Detroit News  

In 2017, Michigan's biggest city posted its lowest tally of criminal homicides in more than a half-century: 267, Detroit Police Chief James Craig confirmed Monday. The program city leaders cite as a factor in falling crime is the expansion of Operation Ceasefire. Craig said he expects to roll out that program citywide by March. It’s currently operating on the east side and in the 6th Precinct on the west side. "We have got the most advanced system of crime intelligence that the police department has ever had," Duggan said. "They are able to pull data instantly; if a shooting happens at 2 a.m, we have the ability to pull data and have a really good idea which groups are involved and be out the next day responding."

Tags: Detroit Group Violence Intervention

New Haven marks lowest homicide number in decades in 2017

December 2017  |  New Haven Register  

With only a day left in 2017, New Haven is on pace for the lowest number of homicides in decades. The seven homicides this year — down from 13 in 2016 — would mark the fewest in New Haven since 2003, when the city had eight.
Both Campbell and Generoso credited the Police Department’s numerous collaborations with the community, and chiefly programs such as Project Longevity and daily interdepartment intelligence meetings, with helping decrease crime rates. Project Longevity combines local, state and federal resources to reduce crime.

Tags: New Haven Group Violence Intervention

York City’s shootings drop by half, GVI credited for reduction

December 2017  |  York Dispatch  

York City had less than half the shootings in 2017 than it had the year before, according to city officials, who credit the national Group Violence Intervention initiative with reducing those numbers. 

The GVI initiative, which began in York City in February after more than a half-year of planning, led to city officers, other law enforcement and GVI community partners making more than 500 contacts with city residents, according to Leitzel.

About 50 or so of those contacts ended with someone being arrested, the lieutenant said, but the vast majority of contacts were positive.

Tags: York Group Violence Intervention

Report: Connecticut’s Project Longevity Is Effective Tool Against Gun Violence

December 2017  |  Hartford Courant  

A new report from a gun policy group founded by former Democratic Congresswoman Gabrielle Giffords highlights Connecticut’s Project Longevity as one of the most effective programs in the nation at combating gun violence.

The state-funded Project Longevity, which has an annual budget of $885,000, was launched in 2012 and operates in New Haven, Hartford and Bridgeport, three cities that account for more than 70 percent of gun homicides in Connecticut. The program targets the small segment of each city’s population that is responsible for the majority of gun crime and seeks to intervene before things turn violent.

Tags: BridgeportHartfordNew Haven Group Violence Intervention