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Police demilitarization and violent crime


Policymakers and advocates make contradictory claims about the effects of providing military equipment to local law enforcement, but this intervention is not well understood because of severe data limitations and inferential challenges. I use 3.8 million archived inventory records to estimate the magnitude of sources of bias in existing studies of the 1033 Program. I show that most variation in militarization comes from previously unobserved sources, which implies that studies that show crime-reduction benefits are unreliable. I then leverage recent policy changes to evaluate the effect of military equipment: the Obama Administration recalled property under Executive Order 13688, which resulted in a forced demilitarization of several hundred departments. Difference-in-difference estimates of agencies that retained similar equipment show negligible or undetectable impacts on violent crime or officer safety. These findings do not suggest that similar scale federal reforms designed to demilitarize police would have the downside risks proposed by proponents of military transfers.

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Fig. 1: Roughly one in five controlled weapons turn over within 4 years.
Fig. 2: Demilitarization did not lead to substantively significant increases or decreases in violent crime or officer safety.
Fig. 3: EO 13688 achieved near-perfect compliance and resulted in demilitarization among affected LEAs.
Fig. 4: Local LEAs with recalled equipment were concentrated in the South, Midwest, and California.

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Data availability

The data supporting the findings reported in this study, along with the underlying 1033 Program inventory records, have been deposited in the Harvard Dataverse and can be found at

Code availability

Replication code for the findings reported in this study has been deposited in the Harvard Dataverse and can be found at:


  1. Kraska, P. B. Enjoying militarism: political/personal dilemmas in studying U.S. police paramilitary units. Justice Q. 13, 405–429 (1996).

    Article  Google Scholar 

  2. Balko, R. Rise of the Warrior Cop: The Militarization of America’s Police Forces (Public Affairs, 2013).

  3. C.J. Coyne & A.R. Hall Tyranny Comes Home: The Domestic Fate of U.S. Militarism (Stanford Univ. Press, 2018).

  4. Phillips, S.W. Police Militarization: Understanding the Perspectives of Police Chiefs, Administrators, and Tactical Officers (Routledge, 2018).

  5. Trump, D. J. Executive Order 13809–restoring state, tribal, and local law enforcement’s access to life-saving equipment and resources. Fed. Regist. 82, 45–59 (2017).

    Google Scholar 

  6. Meeks, D. Police militarization in urban areas: the obscure war against the underclass. Black Scholar 35, 33–41 (2015).

    Article  Google Scholar 

  7. Bates, A. Trump’s decision on military-style weapons will harm communities. USA Today (31 August 2017).

  8. Haynes, J.B. Jr. & McQuoid, A.F. Bringing war home: violent crime, police killings and the overmilitarization of the US police. Preprint at SSRN (2018).

  9. O. Ajilore. Is there a 1033 effect? Police militarization and aggressive policing. Munich Personal RePEc Archive 82543 (2017) .

  10. Haynes, J. B. Jr. & McQuoid, A. F. The thin blue line: police militarization and violent crime. NY Econ. Rev. 49, 26–62 (2018).

    Google Scholar 

  11. Carriere, K.R. & Encinosa, W. The risks of operational militarization: increased confllict against militarized police. Peace Econ. Peace Sci. Public Policy 23, 1–13 (2017).

    Article  Google Scholar 

  12. Bove, V. & Gavrilova, E. Police officer on the frontline or a soldier? The effect of police militarization on crime. Am. Econ. J. Econ. Policy 9, 1–18 (2017).

    Article  Google Scholar 

  13. Delehanty, C., Mewhirter, R., Welch, R. & Wilks, J. Militarization and police violence: the case of the 1033 program. Res. Politics 4, 1–7 (2017).

    Article  Google Scholar 

  14. Gunderson, A., et al. Counterevidence of crime-reduction effects from federal grants of military equipment to local police. Nat. Hum. Behav. (in the press).

  15. Mummolo, J. Militarization fails to enhance police safety or reduce crime but may harm police reputation. Proc. Natl Acad. Sci. USA 11, 1–6 (2018).

    Google Scholar 

  16. Kraska, P. B. & Kappeler, V. E. Militarizing American police: the rise and normalization of paramilitary units. Soc. Prob. 44, 1–18 (1997).

    Article  Google Scholar 

  17. Koslicki, W. SWAT mobilization trends: testing assumptions of police militarization. Policing 40, 733–747 (2017).

    Google Scholar 

  18. Obama, B. H. Executive Order 13688–federal support for local law enforcement equipment acquisition. Fed. Regist. 8, 45–59 (2015).

    Article  Google Scholar 

  19. Simmons, J. P., Nelson, L. D. & Simonsohn, U. False-positive psychology: undisclosed flexibility in data collection and analysis allows presenting anything as significant. Psycol. Sci. 22, 1359–1366 (2011).

    Article  Google Scholar 

  20. Lockwood, B., Doyle, M. & Comiskey, J. Armed, but too dangerous? Factors associated with citizen support for the militarization of the police. Crim. Just. Stud. 31, 113–127 (2018).

    Article  Google Scholar 

  21. Kraska, P. B. Militarization and policing—its relevance to 21st century police. Policing 1, 501–513 (2007).

    Article  Google Scholar 

  22. Bieler, S. Police militarization in the USA: the state of the field. Policing 39, 586–600 (2016).

    Article  Google Scholar 

  23. Rizer, A. & Hartman, J. How the War on Terror has militarized the police. The Atlantic Monthly (2011).

  24. Hall, A. R. & Coyne, C. J. The militarization of U.S. domestic policing. Indep. Rev. 17, 485–504 (2013).

    Google Scholar 

  25. Paul, J. & Birzer, M. L. The militarization of the American police force: a critical assessment. Crit. Issues Just. Politics 1, 15–30 (2008).

    Google Scholar 

  26. Balko, R. Overkill: the Rise of Paramilitary Police Raids in America (Cato Institute, 2006).

  27. Phillips, S. W. & Kim, D.-Y. The effect of police paramilitary unit raids on crime at micro-places in Buffalo, New York. Int. J. Police Sci. Manage.18, 206–219 (2016).

    Article  Google Scholar 

  28. Moule, R. K. Jr., Parry, M. M. & Fox, B. Public support for police use of SWAT: examining the relevance of legitimacy. J Crime Just. 42, 45–59 (2019).

    Article  Google Scholar 

  29. Iacus, S. M., King, G. & Porro, G. Causal inference without balance checking: coarsened exact matching. Polit. Anal. 20, 1–24 (2012).

    Article  Google Scholar 

  30. Mosher, C.J., Hart, T.C. & Terance, T.D. The Mismeasure of Crime (Sage, 2011).

  31. Harris, M. C., Park, J., Bruce, D. J. & Murray, M. N. Peacekeeping force: effects of providing tactical equipment to local law enforcement. Am. Econ. J. Econ. Policy 9, 291–313 (2017).

    Article  Google Scholar 

  32. Law Enforcement Equipment Working Group. Recommendations Pursuant to Executive Order 13688 Federal Support for Local Law Enforcement Equipment Acquisition. (Bureau of Justice Assistance, 2015).

  33. McCarthy, T. & Gambino L. Obama ban on police military gear falls short as critics say it’s a ‘publicity stunt’. The Guardian (1–6 May 2015).

  34. Newland, E. Executive orders in court. Yale Law J. 124, 2026–2099 (2015).

    Google Scholar 

  35. Kaplan J. Uniform crime reporting program data: offenses known and clearances by arrest, 1960–2017 OpenICPSR (2019).

  36. Kaplan J. Uniform crime reporting program data: law enforcement officers killed and assaulted (LEOKA) 1960–2017. OpenICPSR (2019).

  37. Tausanovitch, C. & Warshaw, C. Measuring constituent policy preferences in Congress, state legislatures, and cities. J. Politics 75, 330–342 (2013).

    Article  Google Scholar 

  38. Iacus, S., King, G. & Porro, G. Causal inference without balance checking: software for coarsened exact matching. J. Stat. Softw. 30, 1–24 (2012).

    Google Scholar 

  39. Ajilore, O. The militarization of local law enforcement: is race a factor? Appl. Econ. Lett. 22, 1089–1093 (2015).

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The author received no specific funding for this work. The author thanks K. Crabtree, C. Davenport, J. Mummolo, J. Rogowski, B. Schneer, M. Sen, Y. Shiraito, S. Streeter, Y. Zhukov and seminar audiences at the University of Michigan and Harvard University for comments and suggestions. J. Beckman, A. Eldes, J. Fortney, S. Patel, B. Vomastek and J. Walden provided helpful research assistance.

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K.L. designed and performed the research, analysed the data and wrote the paper.

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Correspondence to Kenneth Lowande.

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Supplementary Methods, Supplementary Results, Supplementary Figs. 1–13 and Supplementary Tables 1–11.

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Lowande, K. Police demilitarization and violent crime. Nat Hum Behav 5, 205–211 (2021).

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