Professor of Criminology and Sociology; Director of the Master of Science in Criminology
PhD, Criminology, University of Maryland, 1999
MA, Criminology, University of Maryland, 1996
BA, Political Science, Vassar College, 1994
John MacDonald is a professor of criminology and sociology in the Department of Criminology at the University of Pennsylvania. His research focuses on policing strategies to reduce crime, racial, and ethnic disparities in policing, police use of force, community–police relations, and the impact of police reforms on officer behavior. He has published over 100 peer-reviewed research articles, 25 book chapters and research reports, and four edited books. He is also the lead author of the 2019 book Changing Places (Princeton University Press), which demonstrates that people’s health and safety can be improved by changing neighborhoods block by block. The book reveals how scientists, practicing planners, developers, and urban residents can work together to create and test place-based interventions that are simple, affordable, and scalable to entire cities.
MacDonald has served for 10 years as a member of the NYPD stop-and-frisk monitoring team, a court-appointed effort to oversee and reform the New York City Police Department's stop-and-frisk practices. This role involves rigorous analysis of data to assess the NYPD's compliance with court-ordered reforms. He has also worked as a consultant for the Los Angeles Sheriff's Department and as a federal court-appointed monitor, where he produced statistical analyses of disparities in police traffic and pedestrian stops. MacDonald is actively engaged in research in partnership with the Chicago Police Department, collaborating with other researchers to examine patterns and practices related to use of force and racial disparities.
MacDonald is co-editor-in-chief of the Journal of Quantitative Criminology and serves as vice-chair of the Committee on Law and Justice at the National Academy of Sciences. He is a fellow of both the American Society of Criminology and the Academy of Experimental Criminology.
Selected Publications:
- Neil, Roland, John M. MacDonald, and Anthony A. Braga. "Sources of organizational variability in fatal police shootings in the USA." Nature Human Behaviour (2025): 1-9.
- MacDonald, John M., Alex Knorre, David Mitre-Becerril, and Aaron Chalfin. "Place-based approaches to reducing violent crime hot spots: A review of the evidence on public health approaches." Aggression and Violent Behavior (2024): 101984.
- Neil, Roland, and John M. MacDonald. "Where racial and ethnic disparities in policing come from: The spatial concentration of arrests across six cities." Criminology & Public Policy 22, no. 1 (2023): 7-34.
- Braga, Anthony A., John M. MacDonald, and James McCabe. "Body‐worn cameras, lawful police stops, and NYPD officer compliance: A cluster randomized controlled trial." Criminology 60, no. 1 (2022): 124-158.
- MacDonald, John, and Anthony A. Braga. "Did post-Floyd et al. reforms reduce racial disparities in NYPD stop, question, and frisk practices? An exploratory analysis using external and internal benchmarks." Justice Quarterly 36, no. 5 (2019): 954-983.
- MacDonald, John, Jeffrey Fagan, and Amanda Geller. "The effects of local police surges on crime and arrests in New York City." PLoS one 11, no. 6 (2016): e0157223.
- MacDonald, John M., Jonathan Klick, and Ben Grunwald. "The effect of private police on crime: evidence from a geographic regression discontinuity design." Journal of the Royal Statistical Society Series A: Statistics in Society 179, no. 3 (2016): 831-846.
- MacDonald, John M., Robert J. Kaminski, and Michael R. Smith. "The effect of less-lethal weapons on injuries in police use-of-force events." American Journal of Public Health 99, no. 12 (2009): 2268-2274.
