This case study is part of the Reimagining Public Safety Impact Updates Resource, which highlights successful programs in cities, towns and villages across the country. View the Reimagining Public Safety Initiative to learn more about NLC’s work in creating safe, equitable communities for all. This is one of four municipalities illustrating Group Violence Intervention, which engages individuals on an interpersonal level to impede continued group violence – with the goal of reducing gun violence and improving community safety.

Philadelphia, PA (pop. 1,603,797): Group Violence Intervention Program 

Philadelphia launched its GVI program in August 2020 to promote community investment and anti-violence, specifically targeting groups and individuals at highest risk for committing violent crimes. In the program’s evaluation, GVI participants spoke positively about the GVI program relationships, services and police officers involved; police officers accordingly noted that the program can change lives. 

More Frequent Participant Engagement with GVI Program is Associated with Greater Reduction in Violence

Source: NLC analysis of GVI program outcomes. Moyer, R. “An Evaluation of the Current Group Violence Intervention (GVI) Implementation in Philadelphia.” University of Pennsylvania, February 2023.
Notes: Philadelphia’s GVI program demonstrates the reduction in shootings for group-units engaging in the GVI program program (post-treatment) one to two times per week, comparing results to pre-treatment. Program evaluation took place January 2020 to May 2022, evaluating 113 group-units receiving GVI treatment.

Due to the health restrictions associated with the COVID-19 pandemic, Philadelphia’s GVI program primarily used mobile call-in teams (MCITs) to engage with high-risk individuals. MCITs operated similarly to a traditional custom notification GVI program: the teams comprised a law enforcement representative who would explain the punitive consequences if violence continued, a community moral voice who would share personal narrative around how they were affected by gun violence, and a social service messenger who would provide transitional employment and case management (participants accepting services receive guaranteed employment with pay through the Center for Employment Opportunity). While traditional call-in meetings were less frequent than the mobile adaptation due to COVID restrictions, Philadelphia held two call-in meetings from 2021-2022 with a total of 27 individuals mandated to attend.

In late 2021, Pennsylvania’s Violence Intervention and Prevention program awarded Philadelphia $2 million over the course of two years to expand GVI and fund 15 additional staff positions. GVI was budgeted at $1.4 million in 2022, which increased to $3.8 million in 2023

Philadelphia’s GVI program is associated with a 38.6 percent reduction in shootings per week for groups who participated in the program one time per week.

Program evaluation demonstrated that there was a 50.3 percent reduction in shootings by individuals who participated with the GVI program two times a week.

From the program’s launch until March 2024, GVI leaders conducted 2,595 custom notifications, 843 direct contacts and 660 collateral contacts with candidates’ family members, resulting in 403 candidates accepting services. The program has generally engaged with individuals who are predominantly low-to moderate-income, Black, male, and ages 19 to 40 years old.  

Philadelphia’s GVI strategy has not only transformed lives of high-risk individuals and reduced gun violence, but the program also has the potential to benefit Philadelphians financially. In 2020, Philadelphia gun injury hospitalizations cost $307.6 million, a 23 percent increase from 2019. From January through November 2021, gun violence cost Philadelphia taxpayers $267.4 million, which accounts only for the victim’s initial hospitalization and does not include the cost of additional follow-up treatments, long-term care or related costs. Reducing group violence through GVI programming can promote community safety and better economic outcomes for the city of Philadelphia.

Key performance metrics include: 

  • Reduction in shootings 
  • Reduction in homicides
  • Number of GVI participants targeted or referred to GVI program
  • Number of custom notifications, direct contacts, and collateral contacts with family members
  • Percent of participants who accepted services

Acknowledgements for contributions and review from Deion Sumpter, MSW. Director of Group Violence Intervention, Office of Violence Prevention, Philadelphia.

View the Reimagining Public Safety Impact Update

Learn more about what different cities have done to support public safety, including qualitative and quantitative measures highlighting the impact of community responder models, group violence interventions, hospital-based violence interventions and community violence interventions.