About

David Pyrooz is a professor in the Department of Sociology at the University of Colorado Boulder. He received his PhD from Arizona State University in 2012 and joined the university's faculty in 2015. His research primarily focuses on the criminology of social groups, particularly gangs, exploring how and why people organize into groups, the criminal and non-criminal consequences for individuals and communities, and responses to gang activity. Pyrooz has been involved as a principal or co-principal investigator on $4.5 million in funding from private and government agencies, with current projects aimed at advancing gang intervention strategies in the Denver area and beyond. He has authored or edited several books, including 'On Gangs' and 'Competing for Control,' the latter of which received the Outstanding Book Award from the Academy of Criminal Justice Sciences. His work has been published in various outlets, and he has received multiple awards, including the Ruth Shonle Cavan Young Scholar Award from the American Society of Criminology in 2016. Pyrooz also serves on the editorial boards of eight refereed journals and is a board member for the Institute of Behavioral Science.

Research topics

• Political Science
• Criminology
• Psychology
• Psychiatry
• Medicine
• Clinical psychology
• Computer Science
• Medical emergency
• Statistics
• Econometrics
• Mathematics
• Virology
• Pathology

Selected publications

• Gang membership, firearm victimization, and mental health in a national sample of U.S. adults

  Injury Epidemiology · 2026-01-24 · 1 citations

  articleOpen access

  BACKGROUND: Firearm violence in the United States is highly concentrated within specific demographic, economic, geographic, and social population groups. Prior research indicates elevated violence exposure among gang-involved individuals, but the extent and mental health implications of firearm victimization at the national level remain poorly understood. METHODS: We analyzed data from a national online survey of 10,000 U.S. adults fielded in 2024. Respondents self-reported lifetime gang membership and lifetime exposure to five forms of firearm victimization: presence at a mass shooting, gun threats, being shot at without injury, accidental gunshot injury, and intentional gunshot injury. Weighted descriptive statistics compared prevalence by lifetime gang status. Multivariable logistic regression estimated adjusted odds ratios controlling for several covariates. Among victims of firearm violence, self-reported psychological impacts, including anxiety, fear, depression, panic attacks, and post-traumatic stress symptoms, were assessed. RESULTS: People with a history of gang involvement reported substantially higher lifetime exposure to all forms of firearm victimization. After adjustment, gang involvement was associated with 2-4 times greater odds of firearm exposure across outcomes. Psychological impacts following firearm victimization were prevalent in both gang and non-gang groups. Differences in reported mental health impacts by gang status were generally modest, with relatively few statistically significant differences in adjusted models. CONCLUSIONS: Firearm victimization is highly concentrated among people with a history of gang involvement, and such exposure is associated with substantial psychological distress. Mental health impacts were broadly similar across gang-involved and non-gang victims. These findings highlight the importance of recognizing gang-involved adults as a population with disproportionate exposure to firearm violence and significant trauma-related needs within a public health framework.

  PublisherDOI

• Non-Gang Eurogang Members? Revisiting Eurogang Measurement in a National Sample

  2026-01-01

  book-chapter1st authorCorresponding
  PublisherDOI

• Are Online Opt-In Panels Viable Data Sources on Hard-to-Reach Populations? Population and Relational Inferences on Gang Membership in the United States

  International Criminology · 2025-06-22 · 6 citations

  articleOpen access1st authorCorresponding

  Abstract Criminologists maintain a vested interest in hard-to-reach populations, such as active offenders, former prisoners, and affiliates of criminal enterprises. For five decades, policymakers and researchers have sought national estimates of gang activity. Traditional methods, such as surveys sampling law enforcement agencies or youth populations, have provided valuable insights into gang activity in the United States and beyond. However, these approaches face limitations, including bias, obsolescence, high costs, outdated data, and restricted scope. This study examines the potential of online opt-in panels to study gang populations. Contracting with YouGov, we administered four surveys to 13,148 respondents between January 2023 and January 2024, measuring lifetime gang membership and its correlates. Lifetime gang membership estimates ranged from 2.0% to 2.4% in custom surveys and 5.3–6.2% in omnibus surveys. While demographic and socioeconomic correlates showed mixed results, ecological and legal correlates consistently aligned with expectations based on prior research. Our findings suggest cautious optimism about the utility of online opt-in panels for studying hard-to-reach populations like gang members and advancing cross-national, comparative research in line with the Eurogang Program of Research. These panels offer advantages, such as cost-efficiency, accessibility, and timeliness, but further validation is necessary to establish their reliability and validity for population-level estimates.

  PublisherOA PDFDOI

• New Directions in the Eurogang Program of Research

  International Criminology · 2025-10-25 · 1 citations

  articleOpen access1st authorCorresponding
  PublisherOA PDFDOI

• Factors Associated With Secure Firearm Storage Among U.S. Gun Owners

  American Journal of Preventive Medicine · 2025-04-17 · 11 citations

  articleOpen access

  INTRODUCTION: This study examines the prevalence of secure firearm storage behaviors through direct and indirect measures, identifies associated factors, and provides insights for targeted public health interventions to reduce gun injury. METHODS: A cross-sectional survey of 10,000 respondents designed to be representative of U.S. adults was administered online in January 2024. Respondents self-reported firearm ownership and storage practices measured directly (locked and unloaded) and indirectly (If you need your firearm in the middle of the night, approximately how long would it take you to have it ready to use?). Multivariable logistic regression models determined demographic, socio-economic, and firearm-related correlates of secure storage. RESULTS: Approximately half of gun owners reported storing their firearms locked and unloaded, while two thirds reported having access in under 60 seconds. Secure storage was more common among women, individuals with children in the home, those who owned fewer firearms, and those whose primary firearm use was for hunting, sport, or collection. Unsecure storage was more prevalent among respondents who reported fears of being shot in various contexts, including at home, in their neighborhood, or at work. Certain demographic and contextual factors, notably, victimization history, political orientation, and the presence of child access prevention laws, were associated with secure storage according to one measure but not the other, highlighting differences in how these practices are measured. CONCLUSIONS: Firearm storage behaviors are largely driven by perceptions of safety, highlighting the need for public health efforts that address fear and tailor messaging to groups less likely to store firearms securely.

  PublisherDOI

• Multidisciplinary teams, street outreach, and gang intervention: Mixed methods findings from a randomized controlled trial in Denver

  Criminology · 2025-08-01

  article1st authorCorresponding

  Abstract Community violence intervention and prevention (CVIP) initiatives aim to develop local infrastructures that inoculate communities from violence. The purpose of this mixed methods study was to evaluate an intervention designed to facilitate disengagement from gangs and desistance from crime. An impact evaluation, based on a preregistered randomized controlled trial, was paired with a process evaluation, based on field observations and interviews, of the Gang Reduction Initiative of Denver's centerpiece intervention that uses multidisciplinary teams (MDTs) and street outreach workers to construct and implement coordinated case plans for high‐risk gang members. The results of the impact evaluation revealed that clients assigned to the intervention were less likely to self‐report perpetrating violence, yet more likely to self‐identify as gang members; judicial records revealed no differences in arrests, charges, or dispositions. The results of the process evaluation indicated that MDTs were effective in securing services for their clients. Despite their limited training and heterogeneous strategies, street outreach workers were viewed positively by their clients and were observed to prioritize behavioral over identity change. These findings are situated within long‐standing tensions and disparate approaches in using outreach workers and targeting of gang behavior and/or involvement in violence reduction strategies, along with large‐scale federal investment in CVIP.

  PublisherDOI

• Experimental effects of a restrictive housing step-down program on violent and non-violent misconduct

  Journal of Criminal Justice · 2025-07-01 · 1 citations

  article
  PublisherDOI

• Mental health consequences of exposure to mass and non-mass shootings in a national sample of US adults

  Nature Mental Health · 2025-04-23 · 7 citations

  articleOpen accessSenior author

  Gun violence exposure is a major public health issue in the United States, yet its mental health consequences remain insufficiently examined. This study investigates the short- and long-term psychological self-reported impacts of lifetime gun violence exposure using a cross-sectional survey of 10,000 respondents designed to be representative of US adults administered online by YouGov in January 2024. Findings revealed that 20.1% of respondents reported a mass shooting in their community, 18.3% had been threatened with a firearm, and 2.2% and 2.4% were injured in mass and non-mass shootings, respectively. Between 58.6% and 94.4% reported mental health consequences across exposure types, with younger individuals and women particularly vulnerable. While mass shootings corresponded with greater psychological distress, the long-term impacts, including post-traumatic stress, were reported at a higher rate following non-mass shootings. These findings promote trauma-informed public health interventions tailored to both individual and community-level needs in the aftermath of gun violence. This study reports short-term and long-term mental health outcomes across several forms of firearm violence exposure using data from an online survey of 10,000 US respondents administered by YouGov and identifies vulnerable groups.

  PublisherOA PDFDOI

• When police pull back: Neighborhood-level effects of de-policing on violent and property crime

  2025-04-04

  preprintOpen access

  Many U.S. cities witnessed both de-policing and increased crime in 2020, yet it remains unclear whether the former contributed to the latter. Indeed, much of what is known about the effects of proactive policing on crime comes from studies that evaluate highly focused interventions atypical of day-to-day policing, use cities as the unit of analysis, or cannot rule out endogeneity. This study addresses each of these issues, thereby advancing the evidence base concerning the effects of policing on crime. Leveraging two exogenous shocks presented by the onset of COVID-19 and social unrest following the murder of George Floyd, we evaluated the effects of sudden and sustained reductions in high-discretion policing on crime at the neighborhood level in Denver. Multilevel models accounting for trends in prior police activity, neighborhood structure, seasonality, and population mobility revealed mixed results. On one hand, large-scale reductions in stops and drug-related arrests were associated with significant increases in violent and property crimes, respectively. On the other hand, fewer disorder arrests did not affect crime. These results were not universal across neighborhoods. We discuss the implications of these findings in light of debates concerning the appropriate role of policing in the 21st century.

  PublisherDOI

• Experimental effects of a restrictive housing step-down program on violent and non-violent misconduct

  CrimRxiv · 2025-07-04 · 1 citations

  preprintOpen access

  Purpose This study addresses two issues that challenge policy, practice, and research on restrictive housing in prisons. First, the overarching need to reduce the footprint of restrictive housing and improve conditions of confinement. Second, the longstanding need to generate credible evidence of the effects of restrictive housing by ruling out selection bias. The Oregon Department of Corrections developed and implemented a step-down program for prisoners in long-term segregation and this study offers experimental evidence of its effects on misconduct. Methods Between 2020 and 2022, 211 prisoners were randomly assigned to either remain in the business-as-usual condition (n=102), the intensive management unit, or voluntarily transfer to the treatment condition (n=109), a newly designed step-down unit. Official records for the full sample were paired with interviews conducted with 112 prisoners about three months post-randomization. Intent-to-treat (ITT) and local average treatment effects (LATE) are reported, testing preregistered hypotheses of official records and self-reports of misconduct in restrictive housing and general population settings. Results Post-randomization ITT and LATE estimates of the step-down unit condition on official report and self-report measures of misconduct in restrictive housing largely indicated null effects, with the exception of an increase in official records of violent misconduct in restrictive housing. Estimates of post-restrictive housing official misconduct in the general population indicated no meaningful group differences between the step-down unit and the business-as-usual conditions. Conclusions The interpretation of findings is limited by the incomplete implementation of the step-down program and disruptions caused by COVID-19. Notably, however, the results suggest it is possible to house people in less restrictive conditions without increases in misconduct upon reentry to the general prison population. This study also serves as a baseline for future assessments and exemplifies how global events can impact correctional research.

  PublisherOA PDFDOI

Recent grants

• Mortality Among High Risk Young Men in the United States

  NIH · $154k · 2019–2022

Frequent coauthors

• Scott H. Decker

  Center for Naval Analyses

  99 shared

• James A. Densley

  Metropolitan State University

  18 shared

• Meghan M. Mitchell

  16 shared

• Richard K. Moule

  University of South Florida

  16 shared

• Jennifer J. Tostlebe

  9 shared

• José Antonio Sánchez

  Texas Christian University

  8 shared

• Scott E. Wolfe

  Michigan State University

  8 shared

• Chantal Fahmy

  The University of Texas at San Antonio

  5 shared

Education

• Ph.D.

  Arizona State University

  2012

Awards & honors

• Outstanding Book Award, Competing for Control: Gangs and the…
• Excellence in Research Award, Boulder Faculty Assembly, Univ…
• Provost’s Faculty Achievement Award, Academic Affairs, Unive…
• Ruth Shonle Cavan Young Scholar Award, American Society of C…
• Academy New Scholar Award, Academy of Criminal Justice Scien…