The origins of the Group Violence Intervention (GVI) can be traced back to the mid-1990s, with the development of Operation Ceasefire in Boston, Massachusetts. This initiative, led by a team from Harvard University’s John F. Kennedy School of Government, David M. Kennedy, Anne M. Piehl, and Anthony Braga, was designed to address homicide through a focused deterrence strategy. It achieved remarkable success, reducing Boston homicides by half and youth homicides by 63 percent during its initial implementation.1
Building on this success, the GVI strategy was formalized as a scalable framework for reducing violence in communities. The approach emphasizes collaboration among the police, community members, and social service providers. The strategy centers on directly engaging with small, identifiable groups responsible for a disproportionate share of gun-related violence, delivering three key messages: (1) a community moral message stating that violence is unacceptable and harmful to the community; (2) a message from service providers tendering and prioritizing assistance and resources; and (3) a law enforcement explanation of the legal risks for violence and a warning that continued violence will result in predictable and certain consequences for the individuals and groups involved. GVI has developed two specific techniques for this direct communication: “call-ins” involving members of multiple groups simultaneously, usually by mandating participation through probation and parole, and “custom notifications,” delivered by the GVI partnership to particular individuals in their homes or elsewhere in the community.
GVI is an evidence-based operational approach that emphasizes collaboration between communities and the police to foster mutual understanding and transparency in order to address gun violence not through punitive measures alone but by creating partnerships that prioritize safety, fairness, and respect. GVI also builds trust through consistent communication, equitable enforcement, and shared accountability.
The natural consequence of this approach is the enhancement of police legitimacy by explicitly breaking with the past practices of over-enforcement and under-protection. Legitimacy is bolstered by moving away from historical patterns of excessive policing in some areas while neglecting others. This shift focuses on implementing fair enforcement practices that prioritize the protection of vulnerable groups while tackling systemic inequalities. By doing this, communities are more likely to view the police as an integral part of their community rather than separate from it, resulting in a perception of fairness and justice.
Based on the central fact that communities are not dangerous, research has consistently shown that in any city, a remarkably small number of people, mostly involved in groups of various kinds—gangs, drug crews, problem families, and the like—are at enormous risk for both violent offending and violence victimization.2 The “problem analysis” that supports GVI typically shows that half or more of homicides and nonfatal shootings are connected to groups representing around ½ percent of the city’s population.3 This finding illustrates that most community members are peaceful and law-abiding, and violence stems from a small subset of individuals; thus, GVI-based interventions focus on addressing these specific actors through community norms, genuine offers of help, and legal warnings, rather than stigmatizing entire neighborhoods or populations.
An additional key element in GVI is recognizing the power of informal social control. Through community moral voices and service providers, the GVI approach not only acknowledges the psychological impact of violence, but it also aims to use community norms, relationships, and networks in regulating violent behavior from people involved in violence; in this way, by empowering local leaders and influencers, this strategy leverages social structures to promote safety and cohesion without relying solely on formal policing, while offering trauma-informed care, counseling, and resources to victims and perpetrators alike, helping them rebuild their lives and preventing further harm.
The use of the community’s informal social control, along with strategic law enforcement, rounds out the intervention, preventing high-risk individuals from killing or being killed. Sparing the use of heavy enforcement sanctions minimizes criminalization while focusing on rehabilitation and prevention.
While GVI represents a proactive intervention approach that emphasizes prevention rather than reactive enforcement, the benefits go beyond improved public safety and lower recidivism rates. By intervening early and effectively, communities and police agencies not only save lives but also avoid the substantial economic and social costs linked to each homicide or nonfatal shooting. Analyzing the financial impact of a single homicide on government resources and private individuals highlights the importance of investing in research-based strategies for violence reduction.
Economic Impacts of GVI
According to the Center for Homicide Research, the economic impact of a homicide goes far beyond the immediate tragedy, including significant government spending and private costs that affect society at large. Research indicates that each homicide carries a huge financial toll, ranging from $1.2 million to $17.25 million per case, depending on the methods used and the cost factors considered.4
The government bears the primary financial burden of homicide cases through various components of the criminal justice system. Direct criminal justice costs for homicide cases are substantial but represent only a fraction of the total economic impact. Police departments allocate significant resources to homicide investigations, encompassing costs associated with crime scene response, police officers and civilian personnel, fire/EMT responders, crime scene cleanup, medical examiner/coroner services, and other related expenses.5
Taxpayers also pay for prosecution, defense, and adjudication costs in the judicial system. These expenses can spike for complex cases requiring extensive legal proceedings.6 Incarceration also represents a substantial ongoing government expense, calculated at about $17.25 million per person imprisoned for homicide.7
“Achieving legitimacy and credibility requires strong interagency coordination, active community participation, and access to social services resources, necessitating sustained partnerships, data analysis capabilities, and coordination across agencies to focus on a small, identifiable population.”
In addition, government-funded health care programs bear significant costs when treating gun violence victims. Emergency care for firearm-related injuries averages $5.47 billion in total costs; government insurance programs cover almost half of all hospital expenses related to gun violence, paying approximately $2.5 billion for survivors in the first year.8
On the private side of the problem, costs imposed on victims’ families and communities, including medical expenses, loss of wages, and decreased productivity, are also substantial and often long-lasting. The community at large also pays a price with increased security measures, business disruptions, and reduced property values in affected communities.
Given the staggering financial burden that gun violence imposes on communities, the implementation of the GVI evidence-based violence prevention strategy represents both a moral imperative and a sound economic investment. The documented success of GVI implementations in multiple countries demonstrates that it can dramatically reduce violence while generating substantial cost savings for governments and communities.
The cost of implementing a GVI strategy varies depending on the city’s size, local needs, and the scope of the work, but it is worth noting that some GVI implementations operate with minimal new funding by reallocating existing city or agency resources. Even if direct GVI funding is decided upon, the cost remains a small part of the economic and human costs of gun violence for cities. For example, during 2020, in Philadelphia, Pennsylvania, hospitalizations for gun injuries alone cost over $300 million, while its annual GVI funding was less than 1 percent of this amount.9
Even with increased funding, GVI investments stay modest compared to the enormous social and economic costs of violence. These findings suggest that expanding GVI funding is a highly cost-effective way to enhance safety and reduce the overall financial burden on cities.10
These robust economic reasons gain even more strength when considering the measurable public safety results that GVI has consistently achieved across different communities. The link between program funding and reduced violence becomes clear when looking at the direct connection between targeted actions and fewer gun violence incidents.
Impacts of GVI
Cities implementing GVI have consistently achieved remarkable results that translate directly into reduced gun violence–related costs. For example, Philadelphia’s GVI strategy resulted in a 38.6 percent reduction in shootings per week among contacted groups.11 Before implementing GVI in 2024, Pine Bluff, Arkansas, saw a 40 percent increase on homicides in 2023, by mid-2025, the city reached a significant milestone of over 500 days without a juvenile homicide.12 Homestead, Florida, reflects a 50 percent reduction in shootings; Davenport, Iowa, has seen shots-fired incidents decrease by 66.7 percent and nonfatal gunshot victims drop by 44.1 percent.13
Implementing a GVI Strategy
GVI operates through a cost-effective model that utilizes existing community resources and strategic partnerships. Concentrating on the small group of high-risk individuals who are responsible for most violence enables targeted resource allocation to maximize impact. This precise focus means that relatively small investments in GVI programs can lead to significant reductions in the large financial burden that homicides place on government and private budgets.
GVI promotes and relies on data-driven decision-making. Although the implementation of the strategy can always be tailored to the needs of any given city or county, genuine adherence to the model’s fidelity is recommended to build robust partnerships among police agencies, community leaders, and service providers. These three foundational elements working synergistically create a methodology that consistently produces reductions in violence when implemented correctly.
“The uniqueness of the GVI model is that its framework is developed to consider law enforcement as a relevant part of the gun violence solution, leveraging existing law and the prospect of actual enforcement to deter violence”
The data-driven approach begins with a thorough problem analysis, consisting of two primary research exercises: the Group Audit and the Incident Review. The Group Audit systematically identifies most or all violent groups in a jurisdiction and maps their areas of operation, alliances, conflicts, estimated membership, key players, levels of organization, and violence, while the second process involves reviewing a jurisdiction’s violent crime incidents over a period for group member involvement either as perpetrators or victims, examining motives, connections to prior and subsequent violence, and other key aspects.14 This analysis provides critical insights into the context of violent incidents, whether victims and wrongdoers are known to practitioners, and how group dynamics drive patterns of violence.
Once the baseline on group violence dynamics is established, the next step should be implementing regular shooting reviews, which are a collaborative breakdown of recent gun-related incidents to understand their underlying causes, group dynamics, and connections to broader patterns of violence, based on a frank conversation on the street experience of knowledgeable police officers and frontline personnel, and consolidating their extensive knowledge into formal intelligence databases, not only to continue the analytical foundation of the work, but to help cities to respond and prevent patterns of violence involving street groups.
Those components of the GVI strategy provide comprehensive data that guide every operational decision during implementation. This information is then shared with a support and outreach working group, which consists of community-based organizations and service providers, to connect with individuals at high risk of violence.
Leading GVI implementations incorporate social network analysis that identifies the structures of street groups through connections contained within police department data and street knowledge from outreach personnel.
This analysis helps understand inter- and intragroup dynamics, aiding in the selection of group members to receive either custom notifications or call-in invitations. Custom notifications are genuine offers of support from community members, police representatives, and service providers, based on their high risk for violent offending, victimization, and criminal justice involvement.15 Call-ins are summons to a face-to-face meeting to address gun- and group-related violence informing participants about the predictable and swift legal consequences they and their groups will face if the violence continues, along with the offer of help and services available to them.16
As mentioned, maintaining fidelity to the GVI model is critical for achieving positive results. The National Network for Safe Communities emphasizes this, stating: “When the strategy is implemented with reasonable fidelity to its core principles—it does not have to be perfect, but it does have to be true to its central ideas—the strategy can produce dramatic results.”17
The key principles for successful implementation are as follows:
- Strategic focus on violence. GVI is not random or reactive policing; it is a coordinated, data-driven strategy that identifies those at the highest risk of involvement in shootings and addresses them with precision, urgency, and compassion.
- Analyzing violence to spot local violent groups and underlying violence dynamics. This analysis is fundamental to recognizing patterns of conflict and how violence spreads through interpersonal and group networks. As GVI seeks to expose the specific context in which violence occurs, responses can be targeted and proportionate.
- Establish a core working group. Bring together partners from law enforcement, community figures, and social services to proactively identify those most at risk of violence, establish moral clarity and social norms, and offer real opportunities for change.
- Direct communication with groups and group members. Those most at risk of involvement in gun violence should receive a credible moral message that violence must stop; a clear warning that further violence will lead to specific and legitimate consequences; and a sincere offer of help.
- Relentless follow-up on every commitment. Maintaining the promises that genuine assistance will remain accessible for those seeking alternatives, while consequences will be certain for those who persist in violence is key for the success of the implementation. Strategic prioritization ensures that dissuasion effects stay meaningful and sustainable without requiring intervention on every individual or incident. This persistent consistency builds credibility and trust, ensuring the strategy remains rooted in transparency, fairness, and accountability.18
Maintaining fidelity to these GVI principles is essential for achieving the model’s intended results. Each core principle works together to strike a carefully balanced mix of responsibility, care, and moral engagement.
As mentioned earlier, the GVI approach can be customized to fit any city’s needs, but it must always stay within the structure; if daily tasks become diluted, ignored, or inconsistently implemented, the strategy’s effectiveness is compromised. Fidelity isn’t restrictive; it’s the foundation for trust, impact, and transformative community safety.
Sustainable Violence Reduction
The type of partnerships that GVI promotes represents a significant shift from traditional police approaches by acknowledging that sustainable violence reduction requires teamwork between police agencies and community-led violence prevention groups. These partnerships ensure accountability and can adjust to changing conditions under the direction and supervision of a project manager.
When it comes to gun violence reduction efforts, GVI is not alone; there are multiple community violence intervention programs (CVI) designed to reduce gun violence by treating it as a public health issue rather than solely a criminal justice problem. CVI programs focus on engaging those most at risk of violence and leverage local resources to interrupt violent incidents, provide support services, and shift social norms.
GVI and CVI are not fundamentally separate approaches; in fact, CVI is integrated into the practice of GVI. Thus, the focused deterrence model of GVI and the public health framework of CVI work together to address violence from multiple angles.
Even though that is true, extensive research and evaluation evidence show that GVI is demonstrably more effective than CVI alone as a violence reduction strategy. The evidence strongly favors GVI’s approach in terms of consistency, reliability, and measurable outcomes. GVI benefits from a robust 30-year research foundation with extensive peer-reviewed evaluations.19 In contrast, CVI alone shows mixed results across implementations.20
The uniqueness of the GVI model is that its framework is developed to consider law enforcement as a relevant part of the gun violence solution, leveraging existing law and the prospect of actual enforcement to deter violence, and, where necessary, incapacitate and deliver actual consequences. This is something that many other gun violence reduction methods do not have in place; moreover, they explicitly avoid partnerships with police.
On the other hand, GVI fuses genuine offers of help and the certainty of swift consequences as mechanisms for behavior change.21 This is condensed in the phrase: “We will help you if you let us, or we will stop you if you make us.” This distinctive approach creates strategic influence by applying enforcement pressure to entire groups when individual members commit violence, creating peer control (informal social control) within groups to discourage violence.
Of course, CVI’s public health intervention model can be integrated with GVI’s support and outreach working groups, bringing together violence interrupters, outreach, and social workers to work in affected communities. These credible messengers, often individuals with lived experience of violence or incarceration, collaborate with service providers and sometimes with police partners to detect and interrupt potentially violent conflicts before they escalate, making sure that their street credibility and positive influence are not affected.
Such an approach to street violence enhances police legitimacy by demonstrating that the police prioritize reducing violence over making arrests, are committed to protecting all—even offenders—and are willing to work collaboratively with communities. Achieving legitimacy and credibility requires strong interagency coordination, active community participation, and access to social services resources, necessitating sustained partnerships, data analysis capabilities, and coordination across agencies to focus on a small, identifiable population.
The evidence base demonstrates that GVI’s structured, partnership-based approach consistently yields strong outcomes across diverse urban contexts, rendering it a more effective primary strategy for communities seeking to reduce group-involved violence.
In summary, GVI provides a comprehensive framework that addresses both the immediate triggers of violence and the long-term factors that draw individuals into violent behavior; it stands as a strong and effective strategy on its own. When other systems are integrated with it, the impact is enhanced, allowing for a more nuanced and coordinated response. This approach empowers individuals and groups to make safer choices while strengthening protection for the broader community.
The phrase “safe, alive, and free” captures the goal of GVI: to ensure individuals can live without fear of violence, enjoy physical safety, and exercise their freedoms, thereby shaping safer communities for all. d
Notes:
1National Network for Safe Communities at John Jay College (NNSC), “Group Violence Intervention”; Anthony A. Braga et al., “Problem-Oriented Policing, Deterrence, and Youth Violence: An Evaluation of Boston’s Operation Ceasefire,” Journal of Research in Crime and Delinquency 38, no.3 (2001): 195-225.
2David M. Kennedy, Don’t Shoot: One Man, a Street Fellowship, and the End of Violence in Inner-City America (New York: Bloomsbury, 2011). David Kennedy discusses how violence is concentrated among small groups in communities and promotes focused deterrence strategies to address it. Also, Andrew V. Papachristos, “Murder by Structure: Dominance Relations and the Social Structure of Gang Homicide,” American Journal of Sociology, 115 no.1 (2009), 74–128, demonstrates how gang and social network structures lead to the concentration of violence in specific networks.
3NNSC, “Group Violence Program Analysis,” fact sheet, 2024.
4Center for Homicide Research, website; Matt DeLisi et al., “Murder by Numbers: Monetary Costs Imposed by a Sample of Homicide Offenders,” The Journal of Forensic Psychiatry & Psychology 21, no. 4 (2010): 501–13.
5National Institute for Criminal Justice Reform, The National Cost of Gun Violence: The Price Tag for Taxpayers (2023).
6The Natasha Minsker, The Hidden Death Tax: The Secret Costs of Seeking the Death Penalty (ACLU of Northern California, 2009), 13–20.
7Ohioans to Stop Executions, fact sheet; DeLisi et al., “Murder by Numbers.”
8Patrick Boyle, “The Cost of Surviving Gun Violence: Who Pays?” AAMC, October 18, 2022.
9National League of Cities, “Philadelphia, PA: Group Violence Intervention,” Reimagining Public Safety Impact Updates, June 25, 2024.
10Center for American Progress, “Community Violence Intervention: Sustainable Funding for Generational Work,” Only in America: The Front Lines of the Gun Violence Crisis (video series), May 23, 2024.
11Ruth A. Moyer, An Evaluation of the Current Group Violence Intervention (GVI) Implementation in Philadelphia (University of Pennsylvania, 2023).
12Isley Gooden, Kaelin Clay, and Scott Solomon, “Pine Bluff Celebrates 500 Days Without Juvenile Homicide With Orange Flair,” KATV, June 6, 2025.
13Homestead Police Department, Internal Report on Group Violence Intervention (2025); Davenport Police Department, “Davenport Police Chief Announces Significant Progress in Public Safety Efforts,” media release, December 4, 2024.
14NNSC, “Problem Analysis,” 2024.
15Flexible, customizable home or street visits that communicate the GVI message. They are often based on recent or anticipated violent incidents, and the recipients’ personal circumstances that leave them particularly vulnerable to sanctions.
16Quarterly or semiannual meetings between the GVI partnership and people representing one or multiple active groups at once.
17NNSC, Group Violence Intervention: An Implementation Guide (Office for Community Oriented Policing, 2015).
18NNSC, Group Violence Intervention: An Implementation Guide.
19College of Policing, “Focused Deterrence Strategies,” January 21, 2022.
20Julia P. Schleimer et al., “Codeveloping Theories of Change for Improved Community-Based Violence Intervention Evaluation,” The Journal of Trauma and Acute Care Surgery 97, no. 2 (2024): 278–285.
21Moyer, An Evaluation of the Current Group Violence Intervention (GVI) Implementation in Philadelphia.
Please cite as
Jaime Ortiz-Aub, “Empowering Safer Choices for Stronger Communities: The Success of the GVI Implementation,” Police Chief Online, November 19, 2025.
