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ICJIA: Violence Interrupters: A Review of the Literature

The street-level violence prevention field includes a range of professionals fulfilling specific roles in various programs. This literature review focuses on violence interrupters as a specific type of outreach worker and the programs that utilize them. Violence interrupters embed themselves within specific areas of communities experiencing elevated levels of violence and mediate emerging conflicts between groups and/or individuals to interrupt the cycle of violence. This review describes the theoretical frameworks guiding the design of these programs, the role of violence interrupters, and program implementations. It also summarizes results from the research literature that evaluates these programs. The literature suggests that violence interrupters are successful at reaching the target population. The research on the effects of these programs on community violence shows that most experience initial success followed by challenges maintaining that success. Program instability from funding and employee turnover likely reduce the effectiveness of VI programs. The dangerous and stressful nature of the work and the relatively poor level of monetary compensation drives the high turnover of VIs. The high social and economic cost of violence suggests that VI programs “pay for themselves” by preventing violence. Overall, evidence suggests violence interrupters are a valuable part of the violence prevention field, but researchers, practitioners, and policy makers need to be aware of violence interrupters’ strengths, limitations, and the supports needed for them to work effectively.
KYLE HUCKE|2024-05-28|


Violence interrupters (VIs) are a specialized form of outreach worker (OW) who specifically focus on violence reduction. OWs have been a key component of many public health focused violence reduction programs (Bonevski et al., 2014). OWs deliver services and/or information directly to individuals in the community with the goal of addressing a particular problem. Researchers sometimes refer to these types of interventions as street-level interventions because the primary point of contact between an OW and the target of the intervention occurs in public, on the street, rather than in a facility or inside the home (Bonevski et al., 2014). The objective is to remove as many barriers as possible by bringing an intervention to the individuals it is designed to help. This tactic can be particularly important for individuals with the greatest risk for involvement in violence (Bonevski et al., 2014). Many of these individuals are part of hard-to-reach or under-resourced populations who might not otherwise be reached by interventions (Bonevski et al., 2014).

VIs bring conflict mediation and anti-violence messaging directly to the individuals who need it the most (Butts et al., 2015; McManus et al., 2020). Violence is often a culmination of escalating tensions between individuals or groups (Butts et al., 2015; McManus et al., 2020). To prevent or reduce it, VIs use direct and indirect pathways (Butts et al., 2015; McManus et al., 2020). Directly, VIs prevent violence in the community by using conflict mediation skills to resolve disputes (Butts et al., 2015). Indirect pathways, by contrast, relate to violence associated with people’s lack of access to adequate resources, such as employment or healthcare (Dahlberg & Mercy, 2009; McManus et al., 2020). In indirect cases, VIs may refer individuals whose conflict they have mediated to another group of OWs (Butts et al., 2015). These OWs, in turn, act as case managers, helping to ensure that the individuals successfully connect to needed resources (Butts et al., 2015). Some programs require VIs to act as hybrids. In these programs, VIs mediate conflict and connect clients to resources (see Figure 1) (Butts et al., 2015). The second indirect pathway is through anti-violence messaging (Skogan et al., 2008). Some violence reduction programs sponsor community events, such as marches and vigils, and promote anti-violence messaging to change community attitudes about violence (Butts et al., 2015). The goal is to create long-term community-level reductions in violence. VIs, OWs, program partners (e.g., faith leaders), and members of the community all participate in these events and spread anti-violence messaging (Butts et al., 2015). This review focuses on violence reduction programs at the individual and community levels that use VIs as part of their program.

Violence Prevention and Violence Interrupters Programs


Historically, many street-level violence prevention programs are law enforcement-based and draw on criminological theory (Dahlberg & Mercy, 2009; McManus et al., 2020). Following high rates of violence in the 1980’s, violence prevention efforts expanded beyond criminology perspectives to include other theoretical frameworks and approaches. Public health is the most prominent of these approaches (Butts et al., 2015; Dahlberg & Mercy, 2009). A public health approach to violence prevention focuses on the well-being of entire populations, emphasizes prevention, and includes multi-disciplinary perspectives and problem-solving techniques (Krug et al., 2002). Under a public health model, economic development and access to mental healthcare are viewed as potential avenues for violence prevention, even though both are outside the purview of law enforcement.

Most programs in this review utilize the public health model, which, by design, treats violence as a communicable disease and aims to target its immediate and root causes to prevent its spread (Butts et al., 2015; Slutkin, Ransford, & Zvetina, 2018). To address the immediate causes of violence, VIs mediate disputes and then, either themselves or someone else from the program, connect individuals to services that can address root causes, such as mental health care. Early examples of these programs include the Little Village Gang Violence Reduction Project in Chicago (1992-1997) and Chicago Ceasefire (later called Cure Violence, 2005-2015) (Skogan et al., 2008; Spergel et al., 2003).

During the early 1990’s, law enforcement-based programs developed new strategies to apply a more targeted approach to crime and violence reduction, such as focused deterrence (Braga, Brunson, & Drakulich, 2019). Focused deterrence is a strategy in which law enforcement targets a specific group of high-risk offenders (e.g., a gang) and tells them they will receive increased enforcement pressure unless the group chooses to discontinue specific behaviors (e.g., gun violence). VIs have been part of programs that use focused deterrence for a long time, as in Boston’s Operation Ceasefire (1996-2000) (Braga, Hureau, & Papachristos, 2014). Initial evaluations of targeted deterrence programs and Cure Violence, such as Chicago Ceasefire and Boston Ceasefire, have deemed both to be promising. Findings have shown that both demonstrate significant reductions in violence, and other cities have adapted, refined, and implemented the programs (Braga, Hureau, & Papachristos, 2014; Skogan et al., 2008).



Public health researchers have suggested that violence can spread like an infectious disease (Slutkin, Ransford, & Zvetina, 2018). Criminological research has indicated that violence is often geographically concentrated, and it pertains to a small group of individuals relative to the size of the entire community who spread it amongst each other (Braga, Papachristos, & Hureau, 2012; Braga & Weisburd, 2012; Braga, Weisburd, & Turchan, 2018; Butts et al., 2015; McManus et al., 2020). These individuals have a high number of risk factors for both perpetrating and being victims of serious violence. In addition, they can be difficult to reach because they can be distrustful of outsiders out of fear of law enforcement (Bonevski et al., 2014). VIs are often formerly members of this population, which leads to more success working with them than others could achieve (Butts et al., 2015). Combined, these research findings inform the design of most of the violence prevention programs in this review (Slutkin, Ransford, & Zvetina, 2018).


Social determinants of health are “the conditions in which people are born, grow, work, live, and age, and the wider set of forces and systems shaping the conditions of daily life” (CDC, 2022). Researchers have developed a social determinants of health framework by drawing on data about chronic health conditions that emphasize the sociological nature of common risk factors, such as poverty (Nation et al., 2021). Within this framework, social determinants are not just variables that are associated with outcomes like chronic disease; they are the root causes of them (Nation et al., 2021).

As an analogy, this framework posits an “environmental contagion” that is the “source” of the disease of violence. Specifically, the sources of pervasive community violence are the social and economic conditions produced by disinvestment policies and practices shaping the community (Sharkey & Marsteller, 2022). Researchers of violence have applied this framework by investigating if relationships exist between a lack of economic stability, quality healthcare, and quality education in a community and its high rates of mortality, morbidity, and violence (Kim, 2019; Nation et al., 2021). Addressing such environmental sources is important in research and practice because, as studies have shown, a common pattern is for violence to return to these communities even after successful violence reduction programs (Sharkey & Marsteller, 2022; Tillyer, Engle, & Lovins, 2012). That is, programs may be treating the symptoms rather than sufficiently addressing the root causes. Many VI programs seek to provide community members with some of the resources they need, but their primary purpose is to prevent the violence that emerges from that need (Butts et al., 2015; McManus et al., 2020).



Cure Violence utilizes the public health approach to address some of the immediate and root causes of violence in communities (Butts et al., 2015). For immediate causes, VIs focus on mediating interpersonal conflicts (Butts et al., 2015). VIs work in areas of the community that are experiencing elevated levels of violence and spend the majority of their time talking to individuals, building rapport in the community, and seeking out conflicts to mediate (Skogan et al., 2008).

Cure Violence also utilizes OWs who act as case managers and connect clients to services (Butts et al., 2015). At the end of a mediation, an individual still may have unmet needs and challenges that are root causes/risk factors of violence, such as poverty or untreated trauma (Skogan et al., 2008; Slutkin, Ransford, & Zvetina, 2018; Smith & Patton, 2016). The goal of ameliorating these unmet needs, with the help of OWs, is to reduce the likelihood that the individual will be in conflicts that could escalate to violence in the future (Butts et al., 2015).

To address community violence, Cure Violence administrators coordinate and build coalitions with other programs and institutions within the community (e.g., local government, faith institutions, other community-based services) (Skogan et al., 2008; Stewart, Jessop, & Watson-Thompson, 2021). These partnerships help to ensure that VIs and OWs have a network of additional services for client referrals and that they have support for community events that spread anti-violence messaging (Skogan et al., 2008; Stewart, Jessop, & Watson-Thompson, 2021).

Studies have shown that Cure Violence programs typically coordinate community activities that are designed to strengthen communal bonds in a neighborhood and to demonstrate a condemnation of violence, such as vigils and marches (Butts et al., 2015). VIs attend these events to reinforce their reputation in the community as leaders seeking to reduce violence (Skogan et al., 2008). Likewise, the events increase the visibility of Cure Violence in the community, which also increases community buy-in for the program (Delgado et al., 2017).


In focused deterrence, law enforcement concentrates on a specific group, usually a gang, and tries to deter them from acts of violence (Braga, Hureau, & Papachristos, 2014). The goal of focused deterrence is to reduce violence, not to increase arrests (Braga, Hureau, & Papachristos, 2014). One of the features that differentiates focused deterrence from a standard policing strategy is the use of “call ins” with a target gang (Braga, Hureau, & Papachristos, 2014). These “call ins” are meetings where law enforcement personnel warn the gang that they are being targeted because of violent behaviors (e.g., gun violence) and that they can avoid a “crack-down” if they discontinue the behavior (Braga, Hureau, & Papachristos, 2014). Gangs that cease the violent acts do not face increased enforcement pressure, but law enforcement “pulls every lever” available to arrest members of the gangs who do not cease the violence (Braga, Hureau, & Papachristos, 2014). These “levers” can include aggressive enforcement of traffic laws, parole violations, and other minor violations as a means of disrupting the gang’s ability to function (Braga, Hureau, & Papachristos, 2014).

Successful “call ins” create a clear cause and effect relationship between the actions of the gangs (i.e. gun violence) and law enforcement’s actions (i.e. the “crack downs”) (Braga, Hureau, & Papachristos, 2014). Establishing that cause and effect gives the gangs some agency to control their relationship with law enforcement and reduces the belief that a “crack down” is arbitrary (Braga, Papachristos, & Hureau, 2012).

VIs contribute to the success of “call ins” by reinforcing the message that law enforcement delivers to the gang. VIs’ role is to increase the likelihood that the gang will believe it (Braga, Hureau, & Papachristos, 2014). This role can be a challenging balancing act for VIs. They must maintain their independence from law enforcement while supporting law enforcement’s call to end violence (Bocanegra et al., 2021; Braga, Hureau, & Papachristos, 2014). Appearing to work with law enforcement can damage their credibility, as many in the community they work with are distrustful of law enforcement (Bocanegra et al., 2021; Braga, Hureau, & Papachristos, 2014). VIs’ abilities to be credible messengers are critical to their specific role in a program utilizing a focused deterrence strategy (Braga, Hureau, & Papachristos, 2014).

Violence Interrupters

Daily Activities

Several studies have used methods such as interviews or surveys to investigate the specific daily activities of VIs. In interviews, VIs talk about establishing strong rapport with members of the community as the first goal of their work, a necessity for mediating conflict successfully (Bocanegra et al., 2021; Decker et al., 2008; DeFries Gallagher, 2021). While VIs describe themselves as better suited to integrate with the target population than others from outside the community, VIs also describe the process of establishing rapport with clients as challenging at times (Bocanegra et al., 2021; Decker et al., 2008; DeFries Gallagher, 2021). VIs state that many of the individuals they have interacted with were part of an insular gang culture or went through life experiences (e.g., trauma from exposure to violence) that made them hesitant to trust others (Bocanegra et al., 2021; Cheng, 2018; Decker et al., 2008; DeFries Gallagher, 2021; Skogan et al., 2008; Smith & Patton, 2016). Researchers also have interviewed Cure Violence supervisors about hiring VIs, and they suggest that a potential VI hire needs to demonstrate such qualities as patience, resilience, passion for the work (DeFries Gallagher, 2021). These qualities are important because, in addition to facing personal danger, VIs are likely to be rebuffed by the people they seek to help and have to respond well to that rejection (DeFries Gallagher, 2021). In spite of these challenges, research has suggested that VIs are able to successfully establish rapport with those who are most in need of their services (Adams & Maguire, 2023; DeFries Gallagher, 2021; Gorman-Smith & Cosey-Gay, 2014; Skogan et al., 2008).

Violence Interrupter Challenges


Researchers have interviewed VIs about the effects of their job on their wellbeing, and results suggest that working as a VI can have a negative impact on an individual’s personal wellbeing (Bocanegra et al., 2021; Free & McDonald, 2022). Researchers have noted that VIs work near violence, and they are at risk for violent victimization; both situations can be traumatic (Bocanegra et al., 2021; Free & McDonald, 2022). In one recent study involving interviews with 35 VIs, 91% report that at least one of their clients was killed within the past year; several of the VIs themselves reportedly have been shot while working as a VI (Bocanegra et al., 2021).

Given the challenges VIs face, they need, but may not always find, reprieves from the difficulties of their work (Bocanegra et al., 2021; DeFries Gallagher, 2021; Free & McDonald, 2022). In research interviews, VIs emphasize that their VI identities exist beyond working hours because community members approach them whenever they are needed (Bocanegra et al., 2021; DeFries Gallagher, 2021; Free & McDonald, 2022). Because violence can happen at any time VIs reportedly feel “always on call” (Bocanegra et al., 2021; DeFries Gallagher, 2021; Free & McDonald, 2022). VIs say they often cannot emotionally distance themselves like other first responders can because they know the victim and/or perpetrator personally (Free & McDonald, 2022). Findings from interviews with VIs suggest they also experience challenges helping others while healing from their own traumas (Harmon-Darrow, 2020). In one study, a VI describes himself as a “wounded healer” (Harmon-Darrow, 2020). Both VIs and their supervisors have stated that the emotional toll of the work contributes to burn-out and high levels of turnover in VI programs (Bocanegra et al., 2021; DeFries Gallagher, 2021; Free & McDonald, 2022). Providing VIs with mental health and financial support, if they are injured, could help alleviate some of the burnout and turnover (Harmon-Darrow, 2020). Currently, it is common for programs to use team meetings as opportunities for VIs to process their emotions and recover from some of the emotional toll of their work (Bocanegra et al., 2021; DeFries Gallagher, 2021; Free & McDonald, 2022).


Several studies have noted that many VIs are in precarious financial situations and/or on short-term contracts without benefits (Bocanegra et al., 2021; Skogan et al., 2008). For instance, VIs from the 2008 Chicago Ceasefire evaluation were on 900 hour contracts that had to be renewed, and the VIs often did not know if they would be renewed (Skogan et al., 2008). More recent research (2021) on different, Chicago-based, VI programs has found that low pay and job stability are significant stressors for VIs (Bocanegra et al., 2021). In one set of interviews, some VIs emphasize their difficulties affording rent and basic goods (Skogan et al., 2008).


As the combined literature has shown, one challenge VIs face is differentiating between high-need and high-risk for violence individuals. In a violence interrupter context, high-risk means that individuals are likely to perpetrate or be the victims of violence; high-need means that individuals lack resources to meet their material needs (e.g. housing or healthcare). It can be difficult for VIs to differentiate between the two because both groups have many common needs, and conditions tied to those common needs can be root causes of violence, like poverty, trauma, and exposure to violence (Dahlberg & Mercy, 2009; Staton et al., 2011). Thus, while not all high-need individuals are high-risk for violence at a given moment, being high-need is a risk factor for becoming high-risk for violence (Farrington, Gaffney, & Ttofi, 2017). Some of the researchers who have evaluated Project REASON, the Cincinnati Initiative to Reduce Violence, and Pittsburgh’s One Vision One Life have postulated that these programs may show reduced efficacy in violence reduction because some VIs focus predominantly on high-need rather than high-risk for violence individuals (Engel, Tillyer, & Corsaro, 2013; Maguire et al., 2019). Researchers and practitioners have created screening tools to identify individuals at the highest risk of violence to aid VIs (Adams & Maguire, 2023; Engel, Tillyer, & Corsaro, 2013; Maguire et al., 2019; Maguire, Oakley, & Corsaro, 2018).

In practice, differentiating high-risk from high-need individuals in order to focus exclusively on those at high-risk can have negative effects. Many community members who are not a high-risk for violence make valid requests for help from VIs (Engel, Tillyer, & Corsaro, 2013). The VIs risk breaking trust or reducing their credibility by not assisting community members when they request assistance (Decker et al., 2008). If a VI or an anti-violence organization gains a reputation for not following through on offers to help, it can be a significant barrier to their efficacy (Gorman-Smith & Cosey-Gay, 2014). Also, researchers have found through interviews that many VIs view their identity and mission more broadly as community service, which includes helping as needed (Bocanegra et al., 2021; Johnson & Everon, 2022). For instance, during the Covid-19 pandemic VIs took on additional duties to help combat the disease even though that was not directly related to violence prevention (Bocanegra et al., 2021; Johnson & Everon, 2022).

Findings from Implementation Evaluations

Funding and Staffing

Unstable and/or inadequate funding is a challenge that has been cited by researchers and the staff of VI programs (Bocanegra et al., 2021; Free & McDonald, 2022; Skogan et al., 2008). Combined findings from several articles underscore that site closures pose a challenge for programs because they create inconsistency for the staff and the community (Bocanegra et al., 2021; Free & McDonald, 2022; Skogan et al., 2008). Temporary suspension of service or closure of sites undermines community faith in the programs (Bocanegra et al., 2021; Free & McDonald, 2022; Johnson & Everson, 2022). Funding challenges contribute to staff turnover, which also impacts the VIs and a program’s relationship with the community (Bocanegra et al., 2021; Free & McDonald, 2022; Johnson & Everson, 2022). Moreover, turnover affects the efficacy of mediations because rapport must be re-established with a new VI, and some knowledge of existing conflicts may be lost when a VI leaves the program (Johnson & Everson, 2022; Whitehill, Webster, & Vernick, 2013).

Political Support

For initial success and sustainability, implementations of VI programs depend on resources, effective leadership, effective communication, and political support for both. Most large VI projects start with political support and initially show success. These effects, however, are difficult to sustain (Butts et al., 2015; McManus et al., 2020). In evaluating the program in New Orleans, researchers have credited strong initial political support as a significant factor in its initial success, with the caveat that “future potential replicating agencies would be well advised to understand the potential toward deterioration of treatment in strategies that approach their second, third, and fourth years” (Corsaro & Engel, 2015). City, state, or federal funding is often the largest source of funding for VI programs. For support, program models include the formation of partnerships with mayoral offices and law enforcement. Both are integral to large-scale sustained community change (Butts et al., 2015; McManus et al., 2020). Decidedly, large-scale community change is slow and irregular compared to election cycles, and changes in leadership can lead to changes in funding priorities.

Program Outcomes

Community Violence

Evaluations have provided mixed results on the effects of VI programs on community violence. The largest and most comprehensive programs, most of which have multiple studies examining them, are in Table 1. In general, the studies evaluating the programs in Table 1 are large-scale studies that have longer intervention periods than other studies discussed in this review (2-5 years), access to more pre-intervention data (2-5 years), and/or comparison groups for the analyses. Access to pre-intervention data allows researchers to measure the effects of the program compared to the conditions in the area prior to implementation.

In general, researchers sought to match the area where the program occurred with a similar area to act as a comparison group. To accomplish this, researchers examined demographic data, economic data, crime statistics, and other important datapoints if they were available. Some studies, such as Safe Streets in Baltimore compared neighborhoods within Baltimore to each other in a quasi-experimental design (Webster et al., 2013). Researchers in other studies, such as the evaluation of Nola for Life in New Orleans, chose to construct the comparison group using data from other cities to achieve the quasi-experimental design because there was not an appropriate neighborhood in New Orleans to act as the comparison (Engel, Tillyer, & Corsaro, 2013).

Table 1 displays the major studies, the primary model used, the primary outcomes measured, and which outcomes achieved statistically significant changes in a positive direction such as reductions in shootings or homicides. Results from researchers’ quantitative analyses of violence rates demonstrate statistically significant reductions of violence in some programs; partial effects in others, varying by specific neighborhood or outcome; and no effect in yet other programs (Butts et al., 2015; McManus et al., 2020). Overall, results suggest that projects using the Cure Violence model alone are less consistently successful at reducing violence at the community level than programs that use multiple strategies.



Program Name, Location, Date Model Used Outcome Measured Results
Ceasefire (Chicago, IL) (2008)
  • Cure Violence
  • Shootings
  • Attempted Shooting
Statistically significant decreases in shootings and attempted shootings in four of seven neighborhoods
Safe Streets (Baltimore, MD)(2013)
  • Cure Violence
  • Homicide
  • Non-fatal shootings
Mixed results depending on neighborhood
Save Our Streets (New York, NY)(2013)
  • Cure Violence
  • Violent Events
  • Shootings
Decrease in total violent events, but an increase in shootings
Project REASON (Trinidad and Tobago)(2018)
  • Cure Violence
  • Violent crimes
  • Hospitalizations for gunshots
  • Calls for emergency services
Statistically significant reductions in all three outcomes
| One Vision One Life (Pittsburgh, PA)(2011)
  • Cure Violence
  • Focused Deterrence
  • Homicide
  • Aggravated assaults
  • Gun assaults
No statistically significant change in homicide rate but a statistically significant increase in aggravated assaults and gun assaults.
NOLA for Life (New Orleans, LA)(2015)
  • Cure Violence
  • Focused Deterrence
  • Homicides
  • Lethal and non-lethal gun violence
Statistically significant reduction in all outcomes, but effects are only attributed to focused deterrence
Cincinnati Initiative to Reduce Violence(Cincinnati, OH)(2013)
  • Cure Violence
  • Focused Deterrence
  • Gang involved homicide
  • Violent firearm incidents
Statistically significant reduction in both outcomes
| Ceasefire Oakland (Oakland, CA)(2019)
  • Focused Deterrence
  • Gun homicide
  • Shootings
Statistically significant reduction in both outcomes
Boston Ceasefire (Boston, MA)(2001)
  • Focused Deterrence
  • Total shootings
Statistically significant reduction in shootings

Cure Violence Programs

Most programs show a significant short-term (12-24 months) improvement in at least one important violence outcome (Butts et al., 2015; McManus et al., 2020). For instance, Chicago Ceasefire demonstrates statistically significant reductions in shootings and homicide in four of seven evaluation sites (Skogan et al., 2008). Initial evaluations of Baltimore’s Safe Streets shows strong effects in the most successful neighborhood demonstrating a 56% reduction in homicide and a 34% reduction in nonfatal shootings (Webster et al., 2013). The other neighborhoods in that study show mixed results (Webster et al., 2013). One has reduced homicides but increased shootings; another has reduced shootings but no change in homicide; and the last shows a decrease in homicide but no change in shootings (Webster et al., 2013).

Many evaluations have offered underlying details about positive effects or the lack of positive effects. Findings from the initial evaluation of Chicago Ceasefire, for example, describe challenges with funding and their likely effects on the future of the program (Skogan et al., 2008). As actual events show, Chicago Ceasefire, despite an initial success, was unable to sustain itself at the level of intervention and under the original organizational structure present in the initial evaluation (Skogan et al., 2008). The original Chicago Ceasefire closed its last site in 2015, though the program was absorbed by Metropolitan Family Services and violence interrupter programs continued to exist in different forms under different organizational leadership to present day (Bocanegra et al., 2021; Chicago Tribune, 2015).

There have also been smaller scale evaluations of other implementations of Cure Violence that either have examined shorter-range outcomes or have lacked a comparison group. For instance, for Advance Peace in Sacramento, a modified version of Cure Violence, evaluations have focused on trauma treatment for clients (Corburn et al., 2021; Corburn, Nidam, & Fukutome-Lopez, 2022). When this program’s interventions were evaluated, gun assaults and homicides had fallen by 21% compared to the previous 18 months (Corburn et al., 2021; Corburn, Nidam, & Fukutome-Lopez, 2022). Data from an implementation of Cure Violence in Honduras show that, compared to the previous nine months, shootings and killings had fallen 73% in three intervention areas (Ransford, Decker, & Slutkin, 2016). However, neither evaluation has included a comparison group so full attribution of the effects to the intervention is not possible.

Focused Deterrence and Cure Violence

Programs that use focused deterrence in conjunction with VIs more consistently show community-wide reductions in violence but also struggle to sustain these effects long-term (Braga, Hureau, & Papachristos, 2014; Braga, Hureau, & Winship, 2008; McManus et al., 2020; Tillyer, Engel, & Lovins, 2012). One example is Operation Ceasefire in Boston. Findings from its evaluations show reduced shootings (31%), yet the program was not sustained when city leadership shifted priorities to funding anti-terrorism efforts (Braga, Hureau, & Winship, 2008; Tillyer, Engle, & Lovins, 2012). The NOLA for Life evaluation has suggested that the focused deterrence portion of the program accounts for the positive effect on reduced violence, but the analysis did not demonstrate a separate effect of the replication of Cure Violence (Corsaro & Engel, 2015).

Attitudes and Norms Concerning Violence

Researchers’ findings on the attitudes of clients with respect to violence suggest that the VIs have a positive effect on the individuals targeted by these programs (DeFries Gallagher, 2021; Gorman-Smith & Cosey-Gay, 2014; Pollack et al., 2011; Skogan et al., 2008). For instance, clients from Chicago report reduced engagement in crime and violence and attribute this reduction to the influence of the VIs (Skogan et al., 2008). Researchers have conducted surveys and interviews with community members to assess the name recognition of programs and attitudes related to violence (Adams & Maguire, 2023; Butts et al., 2015; Gorman-Smith & Cosey-Gay, 2014; Maguire et al., 2019; Maguire, Oakley, & Corsaro, 2018; Milam et al., 2016). Name recognition and support for these programs’ missions are high in most communities and show strong support for anti-violence messaging (Adams & Maguire, 2023; Butts et al., 2015; Gorman-Smith & Cosey-Gay, 2014; Maguire et al., 2019; Maguire, Oakley, & Corsaro, 2018; Milam et al., 2016).

Two sets of researchers have used surveys in Baltimore and New York City, respectively, to compare young men’s attitudes towards violence. Both studies have found that young men in neighborhoods with VI programs report significant reductions in a willingness to use violence over the course of the intervention period compared to young men in neighborhoods without VIs (Delgado et al., 2015; Milam et al., 2016).

Economic Analysis

While a community-wide reduction in violence is an important outcome to pursue, it is not the only metric for evaluating these programs. An additional metric is to consider the economic and social cost of violence compared to the cost of program implementation. Violence incurs a variety of costs that society must bear, such as medical expenses, resources expended by law enforcement, court time, incarceration costs, and loss of economic activity (Waters et al., 2005). Economic analyses of programs in Baltimore, Chicago, and Trinidad and Tobago suggest that these programs save money by preventing violence (Adams & Maguire, 2023; Maguire et al., 2017; Maguire, Oakley, & Corsaro, 2018; READI Chicago, 2020; Webster, Tilchin, & Doucette, 2023). That is, the total cost of incidents of violence prevented is greater than the cost to implement the program that prevented them.

Limitations to Outcome Evaluations

Identifying Appropriate Controls

For evaluations, the strongest experimental design is a randomized control trial, but that design is very challenging for neighborhood-level programs like VI programs and may raise ethical issues. Even quasi-experimental designs, where neighborhoods are not randomly assigned but selected by researchers for the intervention or as controls, are very difficult to implement for VI programs. VIs work in the most violent neighborhoods, which makes it challenging to identify as a control another neighborhood similar in size, demographics, and violence levels (Roman, Klein, & Wolff, 2018). Researchers in Baltimore have found statistically significant differences in violence between intervention neighborhoods and potential control neighborhoods, despite these potential controls still being in the top 20% of violence rates (Webster et al., 2013). Even the largest cities only have a small number of very violent communities with similar characteristics, too small a number for a robust evaluation design. Researchers suggest that an ideal design for testing Cure Violence needs to include at least 15-20 neighborhoods in the experimental group and an equal number in the control group (Butts et al., 2015).

Statistical and methodological techniques can mitigate some of the shortcomings implicit in design limitations, and researchers continue to develop and refine these techniques. One improvement is the use of synthetic controls, which is more robust and reduces the likelihood of unaccounted for, contextual variables (Buggs, Webster, & Crifasi, 2022; Webster, Buggs, & Crifasi, 2018; Webster et al., 2013). Results of these analyses show diminished program effects compared to earlier methods, but researchers have noted a decline in the quality of implementation, as well (Buggs, Webster, & Crifasi, 2022; Webster, Buggs, & Crifasi, 2018; Webster et al., 2013). Making an overarching comment about methodology, researchers examining the Philadelphia implementation of Cure Violence have suggested that, for the purpose of replicating research, the field could benefit from greater transparency in the methods used to construct comparison groups (Roman, Klein, & Wolff, 2018).

Data Quality and Mediation Operationalization

One limitation is that the field has not clearly defined, operationalized, or set clear expectations about mediations. On the one hand, a strict definition of a mediation may lead to excluding interactions that may prevent escalating tensions. On the other hand, a definition that is too broad can lead to a burdensome amount of record keeping. VIs’ interview responses also show that they feel guidance is unclear concerning how many mediations they should engage in and, at times, feel that expectations are not based on their experiences in the field (Bocanegra et al., 2021).

Future Directions


Existing research on VI programs has focused on community-level outcomes, cross-sectional community surveys, and interviews/focus groups with VI staff and clients (Butts et al., 2015; McManus et al., 2020). Longitudinal research at the individual level could provide new information about VI programs. For instance, does mediation success increase as VIs gain experience in the field? Qualitative research describes many challenges that VIs face that lead to burnout or leaving the field (Bocanegra et al., 2021). Addressing these challenges first would provide more long-term viability to the position and make longitudinal research more likely to succeed.

To our knowledge, there has not been a large-scale longitudinal study of outcomes for individual clients of VI programs beyond violence perpetration and victimization. Survey data suggest some other positive outcomes, like increased employment for clients of VI programs (Skogan et al., 2008). Examining such outcomes as incarceration rates of clients, educational attainment, or other indicators of wellbeing could reveal additional positive outcomes of VI programs at the individual level.


This review summarizes and synthesizes the literature examining violence interrupters and the programs that utilized them ranging from programs that were developed in the early 1990’s to the experiences of current VIs. The evidence suggests that violence interrupters are a valuable part of the violence prevention field, but improvements in both programming and evaluation are possible.

  • VIs are successful at reaching the target population.
  • Most VI programs initially reduce violence at the community level, but struggle to maintain that success.
  • Program instability from funding and employee turnover likely reduce the effectiveness of VI programs .
  • The dangerous and stressful nature of the work and the relatively poor level of monetary compensation drives the high turnover of VIs.
  • The high social and economic cost of violence suggests that VI programs “pay for themselves” by preventing violence.

VI programs are designed to identify and target individuals at high-risk for violence, to have VIs mediate escalating conflicts, and to have them connect individuals to services that decrease their likelihood of engaging in violence in the future (Butts et al., 2015). The evidence suggests that VIs are capable of achieving all three of those goals with a population that is difficult to reach and responsible for a disproportionate amount of violence (Bocanegra et al., 2014; Bonevski et al., 2014; Braga et al., 2019; Skogan et al., 2008).

Results for community-level reductions in violence are mixed. Most programs demonstrate at least partial success in the short-term but struggle to sustain results. Researchers have suggested that implementation and funding inconsistencies undermine efficacy with funding shortfalls often being the cause of poor implementation (e.g., sub-optimal staffing levels) (DeFries Gallagher, 2021; Maguire & Adams, 2019; Skogan et al., 2008). Programs with multiple strategies, especially focused deterrence, have tended to yield stronger results, but those multiple strategies also represent increased resource allocation. The literature demonstrates that VI work is dangerous, very challenging emotionally, and poorly compensated (Bocanegra et al., 2021; DeFries Gallagher, 2021). Consequently, there is a high degree of burn-out and turnover for VIs which is both a strain on the programs and likely undermines the effectiveness of the program (Bocanegra et al., 2021; DeFries Gallagher, 2021). Currently, the appropriate number of VIs needed for a community of a given size is unknown as is a strong methodology for estimating the number of “high risk for violence” individuals in a community. Researchers often use violence data at the neighborhood or census tract level because that is what is available, and this size area may be larger than is appropriate for measuring a VI program, but more research is needed (Roman, Klein, & Wolf, 2018). Finally, research suggests that VI programs show success at the individual client level, and economic analyses suggest that the programs are cost effective and save money compared to the cost of violence (Adams & Maguire, 2023; Maguire et al., 2017; Maguire, Oakley, & Corsaro, 2018; READI Chicago, 2020; Webster, Tilchin, & Doucette, 2023).

VI programs are one part of the violence reduction ecosystem (Braga, Weisburd, & Turchan, 2018; Branas et al., 2020; Butts et al., 2015; Riemann, 2019). VI programs provide support to individuals to access services that address needs on an individual level, but they do not directly address the underlying community conditions in which those individuals live (Branas et al., 2020; Powell & Porter, 2022). The challenge VIs face distinguishing “high-need” from “high-risk for violence” individuals highlights the interconnection between those neighborhood conditions and violence (Adams & Maguire, 2023; Wilson & Chermak, 2011). Likewise, the clients of VI programs consistently cite gainful employment as critical to their wellbeing and avoiding future violence (Gorman-Smith & Cosey- Gay, 2014; Maguire et al., 2019; Pollack et al., 2011).

Returning to the social-determinants of violence and the disease analogy, VIs treat those who have already been impacted and prevent the spread of the violence, but they do not significantly address the social determinants of violence to prevent new outbreaks. Investment and revitalization efforts in the communities in which VIs work may reduce the need for mediations while improving the lives of those living in the communities (Branas et al., 2020; Dahlberg & Mercy, 2009; Powell & Porter, 2022; Reimann, 2019).

The author wishes to thank and acknowledge Nick Chanko and Elizabeth St. Mary for their valuable help conducting this review.


Kyle Hucke is a Research Scientist at the Illinois Criminal Justice Information Authority in the Center for Violence Prevention and Intervention Research


This project was supported by legislative appropriation to the Illinois Criminal Justice Information Authority under the Illinois Cannabis Regulation and Tax Act, 410 ILCS 705. The opinions, findings and conclusions expressed in this publication/program/exhibition are those of the authors(s) and do not necessarily reflect the views of the Governor, members of the General Assembly, or the Illinois Criminal Justice Information Authority.


Hucke, K. (2024). Violence Interrupters: A Review of the Literature. Illinois Criminal Justice Information Authority.