Police research and books

It’s strangely common to hear something like, “we _know_ police don’t prevent crime.” It’s a dangerous and false mantra. Sometimes Manning (1979), Gottfredson and Hirschi (1990), Koenig (1991), Tonry (1995), and Bayley (1994) are cited, but I don’t think they even meant that police have no effect on crime. Here is a (partial, in progress) list of academic research and studies that focus on police-centered and police-related crime reductions.

For more ways to reduce violence, see the collection of essays at my Violence Reduction Project.

This list isn’t complete by any means. But I still hope it is a useful resource. My not complete bibliography of much of the research I’ve done can be found here. For whatever reason, it doesn’t include a lot of the references cited in my books.

Updated September 2023. Please feel free to email me new or old articles or books that should be on this list.

Articles on Police and Crime prevention:

Aziai, Alberto. 2022. “What happens when the police go on strike? Analysing how a marked reduction in policing impacts upon homicides in Ceará, Brazil.” Global Crime, DOI: 10.1080/17440572.2022.2098121
The [police] strike led to a statistically significant increase in homicides ranging between 110% and 250%…. Even in a violent context, the perception of a higher risk of apprehension induced by police presence acts as a powerful deterrent against homicides.

Blesse, Sebastian and André Diegmann. 2022. “The place-based effects of police stations on crime: Evidence from station closures.” Journal of Public Economics. Vol. 207. https://doi.org/10.1016/j.jpubeco.2022.104605
Many countries consolidate their police forces by closing down local police stations. Police stations represent an important and visible aspect of the organization of police forces. We provide novel evidence on the effect of centralizing police offices through the closure of local police stations on crime outcomes. Combining matching with a difference-in-differences specification, we find an increase in reported car theft and burglary in residential properties. Our results are consistent with a negative shift in perceived detection risks and are driven by heterogeneous station characteristics. We can rule out alternative explanations such as incapacitation, crime displacement, and changes in police employment or strategies at the regional level. We argue that criminals are less deterred due to a lower visibility of the local police.

Braga, Anthony. 2017. “Editorial introduction. Impact of Police on CJ Reform. Arrests, Harm Reduction, and Police Crime Prevention Policy.” Criminology & Public Policy. Vol. 16(2): 369-373.
Communities expect the police to control violence. Ineffective strategies will undoubtedly undermine police legitimacy. Effective police crime prevention efforts are characterized by changing the perceptions of potential offenders of apprehension risk and by modifying criminal opportunities (Nagin, Solow, and Lum, 2015). Although arrests are inevitable, police should be oriented toward preventing crimes from happening in the first place.

Braga, Anthony A. and Philip J. Cook. 2023. “Policing Gun Violence: Strategic Reforms for Controlling Our Most Pressing Crime Problem.” New York: Oxford University Press.
Argues that it is possible for the police to create greater public safety while respecting the rights of individuals and communities. Violence is itself a root cause of social disparity and future violence. Effective law enforcement is a vital component of a just society. They review and synthesize the evidence in several key areas: enforcement of gun laws, policing hot spots, controlling high-risk groups through focused deterrence, enhancing investigations to increase the arrest and conviction rate, preventing officer-involved shootings, and disrupting underground gun markets.

Braga A., Kennedy D., Pielh A and Waring E. 2001. “Measuring the Impact of Operation Ceasefire in Reducing Gun Violence: The Boston gun project’s operation ceasefire.” NIJ.
The time series shows a 63-percent reduction in the mean monthly number of youth homicide victims from a pretest mean of 3.5 youth homicides per month to a post test mean of 1.3 youth homicides per month. Analyses suggest that the Ceasefire intervention was associated with statistically significant reductions in all time series., including: A 63-percent decrease in the monthly number of youth homicides in Boston. A 32-percent decrease in the monthly number of citywide shots-fired calls. A 25-percent decrease in the monthly number of citywide all-age gun assault incidents.

Braga, Anthony A., Andrew V. Papachristos & David M. Hureau (2012). “The Effects of Hot Spots Policing on Crime: An Updated Systematic Review and Meta-Analysis.” Justice Quarterly. Vol. 31(4): 633-663.
Abstract: Our research suggests that hot spots policing generates small but noteworthy crime reductions, and these crime control benefits diffuse into areas immediately surrounding targeted crime hot spots. Our analyses find that problem-oriented policing interventions generate larger mean effect sizes when compared to interventions that simply increase levels of traditional police actions in crime hot spots. We also find that only a small number of studies examine the impacts of hot spots policing on police-community relations. The extant research on this topic, however, suggests that community members have positive reactions to these focused policing actions. [See also: Braga et al, 2018, “An Updated Systematic Review and Meta-Analysis of the Empirical Evidence.”]

Braga A., Weisburd, D., Turchan, B. 2018. “An Updated Systematic Review and Meta-Analysis of the Empirical Evidence.” Criminology & Public Policy. Volume 17. Issue 1.
The results of our meta-analysis demonstrate that focused deterrence strategies are associated with an overall statistically significant, moderate crime reduction effect.

Braga, A. A., D. L. Weisburd, E. J. Waring, L. G. Mazerolle, W. Spelman, & F. Gajewski. “Problem-Oriented Policing in Violent Crime Places: A Randomized Controlled Experiment.” Justice Quarterly. Vol 31(4): 633-663.
Many researchers believe that crime problems can be reduced more efficiently if officers systematically focus their attention on crime “hot spots.” Previously, the value of focused problem-oriented policing efforts in controlling violence was not known. This randomized controlled experiment […] concluded that the Jersey City Police Department’s pilot problem-oriented policing program was successful at reducing crime and disorder at violent places, with little evidence of displacement.

Braga, Anthony A., Brandon C. Welsh, and Cory Schnell. 2015. “Can policing disorder reduce crime? A systematic review and meta-analysis.” Journal of Research in Crime and Delinquency. Vol. 52: 567–588.
Suggests that hot spots policing generates small but noteworthy crime reductions, and these crime control benefits diffuse into areas immediately surrounding targeted crime hot spots. Our analyses find that problem-oriented policing interventions generate larger mean effect sizes when compared to interventions that simply increase levels of traditional police actions in crime hot spots. [See also: Braga et al, 2018, “An Updated Systematic Review and Meta-Analysis of the Empirical Evidence.”]

Chalfin, Aaron, Michael LaForest, and Jacob Kaplan. 2021. “Can Precision Policing Reduce Gun Violence? Evidence from ‘Gang Takedowns’ in New York City.” Journal of Policy Analysis and Management. Vol 40(4), pp. 1047-1082. https://onlinelibrary.wiley.com/doi/10.1002/pam.22323
During the last decade, while national homicide rates have remained flat, New York City has experienced a second great crime decline, with gun violence declining by more than 50 percent since 2011. In this paper, we investigate one potential explanation for this dramatic and unexpected improvement in public safety—the New York Police Department’s shift to a more surgical form of “precision policing,” in which law enforcement focuses resources on a small number of individuals who are thought to be the primary drivers of violence. We study New York City’s campaign of “gang takedowns” in which suspected members of criminal gangs were arrested in highly coordinated raids and prosecuted on conspiracy charges. We show that gun violence in and around public housing communities fell by approximately one third in the first year after a gang takedown. Our estimates imply that gang takedowns explain nearly one quarter of the decline in gun violence in New York City’s public housing communities over the last eight years.

Chalfin and McCrary. 2012. “The Effect of Police on Crime: New Evidence from U.S. Cities, 1960-2010.”
https://eml.berkeley.edu//~jmccrary/chalfin_mccrary2012.pdf

“The Challenge of Crime in a Free Society: A report by the President’s Commission on Law Enforcement and Administration of Justice.” 1967. Washington, D.C.: Government Printing Office.
Moreover, there have been a number of demonstrations that increasing the patrol force in an area, through use of special tactical patrols, causes a decline in crimes directed at citizen walking the streets in the heavily patrolled area. The number of crime committed in the New York subways also declined by 36.1 percent last year [I presume 1966?] after a uniformed transit patrolman was assigned to every train during the late night hours.

Cheng, Cheng, Wei Long, 2019. “Improving police services: Evidence from the French Quarter Task Force.” Journal of Public Economics, Vol. 164, pp. 1-18,
https://doi.org/10.1016/j.jpubeco.2018.05.002.
Abstract: This study sheds light on the improvement of police services by examining the French Quarter Task Force (FQTF) – an anti-crime program in New Orleans’ French Quarter. First, we provide new evidence that increasing police presence is effective in crime prevention. Our difference-in-differences estimates suggest that the FQTF, which increased police visibility in the French Quarter, reduced robberies, aggravated assaults, and thefts by 37.4%, 16.9%, and 13%, respectively. Second, our findings imply that the proper use of monitoring and incentive strategies has the potential to further improve police services. Exploiting the program’s change in management, we find that providing officers with more monitoring and performance incentives led the FQTF to reduce robberies by 22.12 and aggravated assaults by 5.56 each quarter.

Chalfin A. and McCrary J. 2018. “Are U.S. Cities Underpoliced? Theory and Evidence.” The Review of Economics and Statistics. Vol. 100(1): 167–186.
https://eml.berkeley.edu/~jmccrary/chalfin_mccrary2018.pdf
We document the extent of measurement errors in the basic data set on police used in the literature on the effect of police on crime. Analyzing medium to large U.S. cities over 1960 to 2010, we obtain measurement error-corrected estimates of the police elasticity. The magnitudes of our estimates are similar to those obtained in the quasi-experimental literature, but our approach yields much greater parameter certainty for the most costly crimes, the key parameters for welfare analysis. Our analysis suggests that U.S. cities are substantially underpoliced.

Chalfin, Aaron, Benjamin Hansen, Emily K. Weisburst & Morgan C. Williams, Jr. 2020. “Police Force Size and Civilian Race.” NBER: National Bureau of Economic Research. December.
https://www.nber.org/papers/w28202
Abstract: We report the first empirical estimate of the race-specific effects of larger police forces in the United States. Each additional police officer abates approximately 0.1 homicides. In per capita terms, effects are twice as large for Black versus white victims. At the same time, larger police forces make more arrests for low-level “quality-of-life” offenses, with effects that imply a disproportionate burden for Black Americans. Notably, cities with large Black populations do not share equally in the benefits of investments in police manpower. Our results provide novel empirical support for the popular narrative that Black communities are simultaneously over and under-policed.

Cook, P.J. and MacDonald J. (2011). “Public safety through private action: An economic assessment of bids.” The Economic Journal. Vol. 121 (May): 445-462.
Our analysis of 30 Los Angeles BIDs demonstrates that the social benefits of BID expenditures on security are a large multiple (about 20) of the private expenditures. Crime displacement appears minimal. Crime reduction in the BID areas has been accompanied by a reduction in arrests, suggesting further savings.

Di Tella, Rafael, and Ernesto Schargrodsky. 2004. “Do Police Reduce Crime? Estimates Using the Allocation of Police Forces After a Terrorist Attack.” American Economic Review. Vol. 94 (1): 115-133.
An important challenge in the crime literature is to isolate causal effects of police on crime. Following a terrorist attack on the main Jewish center in Buenos Aires, Argentina, in July 1994, all Jewish institutions received police protection. Thus, this hideous event induced a geographical allocation of police forces that can be presumed exogenous in a crime regression. Using data on the location of car thefts before and after the attack, we find a large deterrent effect of observable police on crime. The effect is local, with no appreciable impact outside the narrow area in which the police are deployed.

Draca, Mirko, Stephen Machin, and Robert Witt. 2011. “Panic on the Streets of London: Police, Crime, and the July 2005 Terror Attacks.” American Economic Review. Vol. 101 (August): 2157–2181.
We find strong evidence that more police lead to reductions in what we refer to as susceptible crimes (i.e., those that are more likely to be prevented by police visibility, including street crimes like robberies and thefts). Our starting point is the basic insight at the center of Di Tella and Schargrodsky’s (2004) paper, namely, that terrorist attacks can induce exogenous variations in the allocation of police resources that can be used to estimate the causal impact of police on crime. … The research design delivers some striking results. There is clear evidence that the timing and location of falls in susceptible crimes closely coincide with the increase in police deployment. Crime rates quickly returned to pre-attack levels after the six week “policy-on” period.

Engel, Robin S., Nicholas Corsaro, and M. Murat Ozer. 2017. “The impact of police on criminal justice reform: Evidence from Cincinnati, Ohio.” Criminology & Public Policy. Vol. 16: 375–402.
A case study and policy analysis of how police can be effective in crime prevention while economizing on the use of arrests. They show that the Cincinnati Police Department were successful in significantly reducing both violent crime and arrests, and they suggest this was achieved by changing officer views of arrests from a standard response to crime incidents to a limited commodity that should be used sparingly. A blueprint for how police departments could and should be oriented toward the use of arrest in crime control and prevention.

Fox, B., Allen, S. F. & Toth, A. (2021). “Evaluating the impact of Project Safe Neighborhoods (PSN) initiative on violence and gun crime in Tampa: does it work and does it last?” Journal of Experimental Criminology. March.
A 3-year post-intervention study of a project that targeted deterrence and enforcement efforts for a select group of ‘VIP’ prolific offenders in Tampa, FL, was associated with an overall 24% reduction in violent crimes and gun crimes over the entire post-test period. Total arrests in the treatment jurisdiction also decreased.

Hinkle, Joshua C., David Weisburd, Cody W. Telep, and Kevin Petersen (2020). “Problem-oriented policing for reducing crime and disorder: An updated systematic review and meta-analysis.” Campbell Systematic Reviews. Vol. 16(2).
https://doi.org/10.1002/cl2.1089
Problem-oriented policing (POP) is associated with statistically significant reductions in crime and disorder. Place-based POP programs are more likely to produce a diffusion of benefits into areas adjacent to targeted locations than to lead to crime displacement.

Klick J. & Tabarrok A. “Using terror alert levels to estimate the effect of police on crime.” Journal of law and economics, vol. XLVIII (April 2005).
Changes in the terror alert level set by the Department of Homeland Security provide a shock to police presence in Washington, D.C. Using daily crime data during the period the terror alert system has been in place, we show that the level of crime decreases significantly, both statistically and economically, in Washington, D.C., during high-alert periods. The decrease in the level of crime is especially large in the National Mall. This provides strong evidence of the causal effect of police on the level of crime and suggests a research strategy that can be used in other cities.

MacDonald, John, Jeffrey Fagan, and Amanda Geller. (2016). “The effects of local police surges on crime and arrests in New York City.” PLoS ONE. Vol. 11(6): e0157223.
The New York Police Department (NYPD) under Operation Impact deployed extra police officers to high crime areas designated as impact zones. Officers were encouraged to conduct investigative stops in these areas. City officials credited the program as one of the leading causes of New York City’s low crime rate. We tested the effects of Operation Impact on reported crimes and arrests from 2004 to 2012 using a difference-in-differences approach. We used Poisson regression models to compare differences in crime and arrest counts before and after census block groups were designated as impact zones compared to census block groups in the same NYPD precincts but outside impact zones. Impact zones were significantly associated with reductions in total reported crimes, assaults, burglaries, drug violations, misdemeanor crimes, felony property crimes, robberies, and felony violent crimes. Impact zones were significantly associated with increases in total reported arrests, arrests for burglary, arrests for weapons, arrests for misdemeanor crimes, and arrests for property felony crimes. Impact zones were also significantly associated with increases in investigative stops for suspected crimes, but only the increase in stops made based on probable cause indicators of criminal behaviors were associated with crime reductions. The largest increase in investigative stops in impact zones was based on indicators of suspicious behavior that had no measurable effect on crime. The findings suggest that saturating high crime blocks with police helped reduce crime in New York City, but that the bulk of the investigative stops did not play an important role in the crime reductions. The findings indicate that crime reduction can be achieved with more focused investigative stops.

MacDonald J, Klick J, and Grunwald B. 2016. “The effect of private police on crime: evidence from a geographic regression discontinuity design.” Journal of the Royal Statistical Society Series A. (2016) 179, Part 3, pp. 831–846.
https://www.law.upenn.edu/live/files/8949-179jrss831pdf

MacDonald J, Klick J, and Grunwald B. 2016. “The effect of private police on crime: evidence from a geographic regression discontinuity design.” Journal of the Royal Statistical Society Series A. (2016) 179, Part 3, pp. 831–846.
https://www.law.upenn.edu/live/files/8949-179jrss831pdf
Research demonstrates that police reduce crime. We study this question by using a natural experiment in which a private university increased the number of police patrols within an arbitrarily defined geographic boundary. Capitalizing on the discontinuity in patrols at the boundary, we estimate that the extra police decreased crime in adjacent city blocks by 43–73%. Our results are consistent with findings from prior work that used other kinds of natural experiment. The paper demonstrates the utility of the geographic regression discontinuity design for estimating the effects of extra public or private services on a variety of outcomes.

Mello S. 2019. “More COPS, less crime.” Journal of Public Economics. Vol. 172 (April): 174-200.
Recovery Act grants to local police departments increased police forces.  Each additional police officer prevented 4 violent crimes and 15 property crimes. On average, the social value of a marginal police officer exceeds $300,000. Impacts on crime were largest in areas most affected by the Great Recession.

Mohler, G.O., M.B. Short, Sean Malinowski, Mark Johnson, G.E. Tita, Andrea L. Bertozzi, and P. J. Brantingham. 2016. “Randomized Controlled Field Trials of Predictive Policing.” Journal of the American Statistical Association. Vol. 110(2015-512).
https://doi.org/10.1080/01621459.2015.1077710
While previous hotspot policing experiments fix treatment and control hotspots throughout the experimental period, we use a novel experimental design to allow treatment and control hotspots to change dynamically over the course of the experiment. Our results show that ETAS models predict 1.4–2.2 times as much crime compared to a dedicated crime analyst using existing criminal intelligence and hotspot mapping practice. Police patrols using ETAS forecasts led to an average 7.4% reduction in crime volume as a function of patrol time, whereas patrols based upon analyst predictions showed no significant effect. Dynamic police patrol in response to ETAS crime forecasts can disrupt opportunities for crime and lead to real crime reductions.

Nagin, Daniel S., Robert M. Solow, and Cynthia Lum. 2015. “Deterrence, criminal opportunities, and the police.” Criminology. Vol. 53: 74–100.
Effective police crime prevention efforts are characterized by changing the perceptions of potential offenders of apprehension risk and by modifying criminal opportunities.

Ratcliffe, Jerry H., Amber Perenzin, Evan T. Sorg. 2017. “Operation Thumbs Down: A quasi-experimental evaluation of an FBI gang takedown in South Central Los Angeles.” Policing: An International Journal. Vol. 40 No. 2, pp. 442-458. https://doi.org/10.1108/PIJPSM-01-2016-0004
Findings: A statistically significant 22 percent reduction in violent crime was observed, a reduction that lasted at least nine months after the interdiction.

Ratcliffe, J and Sorg E. 2017. “The Philadelphia Experience.” In Ratcliffe, J and Sorg E. Foot Patrol: Rethinking the Cornerstone of Policing. Springer.
The Philadelphia Experiment represented a major examination of this concept, involving over 200 officers in 60 locations over a two-year period, in some of the highest violent crime areas of Philadelphia. The results suggested that a targeted hot spots-oriented foot patrol strategy did contribute to violent crime reduction.

Roeder O., Eisen L., Bowling J. 2015. “What Caused the Crime Decline?” Brennan Center.
https://www.brennancenter.org/sites/default/files/2019-08/Report_What_Caused_The_Crime_Decline.pdf
Based on an analysis of the 50 most populous cities, this report finds that CompStat-style programs were responsible for a 5 to 15 percent decrease in crime in those cities that introduced it. Increased numbers of police officers also played a role in reducing crime.

Smith D. and Purtell R. (2007). “An Empirical Assessment of NYPD’s ‘Operation Impact’: A Targeted Zone Crime Reduction Strategy.”
https://marroninstitute.nyu.edu/uploads/content/Dennis_Smith_Impact_Zone_Policing_Report.pdf
Precincts that were assigned Impact Zones starting in 2003 experienced a 24%  acceleration in declining murder rates,  a more than doubling of the rate of decline in rapes and grand larcenies, a 21% boost in the decline of robbery rate and of 23% in assault rate by 2006.

Wang, J. & Weatherburn, D. (2021). “The effect of police searches and move-on directions on property and violent crime in New South Wales.” Journal of Criminology.
When one Australian state brought in legislation that gave police the power to stop, search and detain a person without warrant under particular circumstances or tell them to move on, they found increases in the use of these powers reduced robbery, burglary and vehicle theft.

Weisburst, Emily. 2019. “Safety in Police Numbers: Evidence of Police Effectiveness from Federal COPS Grant Applications.” American Law and Economics Review. Vol. 21(1):81–109. Spring.
https://academic.oup.com/aler/article/21/1/81/5210860
Using data from nearly 7,000 U.S. municipalities, [Results show] that a 10% increase in police employment rates reduces violent crime rates by 13% and property crime rates by 7%.

Weisburd, David and Taryn Zastrow. 2021. “Crime Hot Spots: A Study of New York City Streets in 2010, 2015, and 2020.” Manhattan Institute.
Summary: https://www.manhattan-institute.org/weisburd-zastrow-crime-hot-spots
Article: https://media4.manhattan-institute.org/sites/default/files/weisburd-zastrow-crime-hot-spots.pdf
It is misleading to classify whole neighborhoods as crime hot spots, since the majority of streets—even in higher-crime areas—are not…. It is clear from our data that many city streets still have very high crime levels, requiring interventions by police and city government more generally.

Weisburd, Sarit. 2021. “Police Presence, Rapid Response Rates, and Crime Prevention.” The Review of Economics and Statistics. Vol. 103 (2): 280–293.
https://direct.mit.edu/rest/article-abstract/103/2/280/97658/Police-Presence-Rapid-Response-Rates-and-Crime?redirectedFrom=fulltext
This paper estimates the impact of police presence on crime using a unique database that tracks the exact location of Dallas Police Department patrol cars throughout 2009. To address the concern that officer location is often driven by crime, my instrument exploits police responses to calls outside their allocated coverage beat. This variable provides a plausible shift in police presence within the abandoned beat that is driven by the police goal of minimizing response times. I find that a 10% decrease in police presence at that location results in a 7% increase in crime. This result sheds light on the black box of policing and crime and suggests that routine changes in police patrol can have a significant impact on criminal behavior.

Wells, W., Zhang, Y. & Zhao, J. (2012). “The effects of gun possession arrests made by a proactive police patrol unit.” Policing: An International Journal of Police Strategies & Management. Vol. 35(2): 253-271.
Citywide, each arrest by Houston PD’s Crime Reduction Unit was linked to a reduction of about 2.4 offences committed with a gun the following week. (Wells et al., 2012)

Wheeler, A. P., Riddell, J. R. & Haberman, C. P. (2021). “Breaking the chain: How arrests reduce the probability of near repeat crimes.” Criminal Justice Review.
Near repeat crime clusters is space and time, such as retaliatory shootings. Analysis of data from Dallas suggests arrests can interrupt the chain and reduce repeat events by 20-40%.

Wilson, James Q. 1979. The Effect of the Police on Crime. Washington, D.C.: U.S. Department of Justice.
The effect of police practices on the rate of robbery in 35 large American cities is estimated by a set of simultaneous equations.  The measures of police resources (patrol units on the street) and police activity on the street (moving violations issued) are more precise than anything thus far available in studies of this kind and permit the use of identification restrictions that allow stronger inferences about the causal effect of arrests on crime rates than has heretofore been possible.  Police resources and police activity independently affect the robbery rate after controlling for various socioeconomic factors. 

Wilson, J. Q. & Boland, B. (1978). “The effect of the police on crime.” Law and Society Review. Vol. 12(3): 367-390.
Higher levels of street level law enforcement (as proxied by moving violations) across 35 cities were associated with lower levels of robbery.

Wilson, James Q. and George L. Kelling. 1982. “Broken Windows: The Police and Neighborhood Safety.” The Atlantic. March: 29-38.

Wyant, B. R., Taylor, R. B., Ratcliffe, J. H. & Wood, J. (2012). “Deterrence, firearm arrests, and subsequent shootings: A micro-level spatio-temporal analysis.” Justice Quarterly. Vol. 29(4): 524-545.
In Philadelphia, following a firearms arrest, shootings declined significantly by 28–47% up to a couple of blocks away.

Zimring, Frank. 2011. “How New York City Beat Crime.” Scientific American. August.
https://www.scientificamerican.com/article/how-new-york-beat-crime/
With its judicious use of cops and innovative methods, the Big Apple is a model for how to stem homicides, muggings and other ills.

Research Summaries:

Experts agree: https://www.niskanencenter.org/reducing-gun-violence-what-do-the-experts-think/. More on “expert” (which I’m not, apparently) consensus: https://cjexpertpanel.org/surveys/policing-and-public-safety/
Crime denialist disagree: https://www.city-journal.org/third-ways-misdirection-on-violent-crime.
Evidence-Based Policing Matrix (personally I never been able to understand this graphic, but maybe it’s just me. Still clicking on the circles to show the study is pretty cool.) https://cebcp.org/evidence-based-policing/the-matrix/
Non police approaches: “Reducing Violence Without Police: A Review of Research Evidence.” John Jay College Research Advisory Group on Preventing and Reducing Community Violence (2020). New York, NY: Research and Evaluation Center, John Jay College of Criminal Justice, City University of New York. https://johnjayrec.nyc/2020/11/09/av2020/
Violence interrupters: “The evidence for violence interrupters doesn’t support the hype: In the quest for alternatives to police, interrupters simply aren’t a proven idea.” German Lopez, 2021. Sep 3, 2021.
https://www.vox.com/22622363/police-violence-interrupters-cure-violence-research-study

Banton, Michael. 1964. The Policeman in the Community. New York: Basic Books.

Critchley, T.A. 1967. A History of Police in England and Wales 900-1966. London: Constable and Company Ltd.

Donnelly, Daniel. 2008. Municipal Policing in Scotland. Dundee (Scotland): Dundee University Press.

Dulaney, W. Marvin. 1996. Black Police in America. Bloomington, Indiana: Indiana University Press.

Emsley, Clive. 1991. The English Police: A Political and Social History. London: Harvester Wheatsheaf.

Fogelson, Robert M. 1977. Big-City Police. Cambridge: Harvard University Press.

Folsom, De Fancias. 1888. Our Police: A History of the Baltimore Force From the First Watchman to the Latest Appointee. Baltimore, Maryland: J.D. Ehlers.

Goldstein, Herman. 1990. Problem-Oriented Policing. New York: McGraw-Hill.

Jackall, Robert. 1997. Wild Cowboys: Urban Marauders & the Forces of Order. Cambridge, Massachusetts: Harvard University Press.

Johnson, David Ralph. 1981. American Law Enforcement: A History. Wheeling, Ill: Forum Press.

Klockars, Carl B. 1980. “The Dirty Harry Problem.” In The Annals, 452 (November 1980), pp. 22-47.

Lee, William Lauriston Melville. 1901. A History of Police in England. London: Methuen. (1971. Montclair, N.J.: Patterson Smith.)

Manning, Peter K. 1977. Police Work: the Social Organization of Policing. Cambridge: The Massachusetts Institute of Technology.

Miller, Wilbur R. 1975. “Cops and Bobbies, 1830-1870.” From “Police Authority in London and New York City 1830-1870,” from the Journal of Social History (Winter 1975), pp. 81-101.

Monkkonen, Eric H. 1981. Police in Urban America: 1860 – 1920. Cambridge: Cambridge University Press.

Moskos, Peter. 2009. Cop in the Hood. Princeton University Press.

Moskos, Peter, 2025. Back from the Brink. Oxford University Press.

Muir, William Ker, Jr. 1977. Police: Streetcorner Politicians. Chicago: The University of Chicago Press.

Niederhoffer, Arthur. 1967. Behind the Shield: the Police in Urban Society. Garden City, New York: Doubleday & Company.

Punch, Maurice. 1979. Policing the Inner City: A Study of Amsterdam’s Warmoesstraat. London: The Macmillan Press Ltd.

Reiner, Robert. 1992. The Politics of the Police. Toronto: University of Toronto Press.

Reith, Charles. 1948. A Short History of the British Police. London: Oxford University Press.

Reith, Charles. 1956. A New Study of Police History. Edinburgh: Oliver and Boyd.

Reuss-Ianni, Elizabeth. 1983. Two Cultures of Policing. New Brunswick, NJ: Transaction Books.

Skogan, Wesley G. 1990. Disorder and Decline: Crime and Spiral of Decay in America. New York: The Free Press.

Skolnick, Jerome H. and James J. Fyfe. 1993. Above the Law: Police and the Excessive Use of Force. New York: The Free Press.

Van Maanen, John. 1978. “The Asshole,” Policing: A View from the Street, Peter K. Manning and John Van Maanen (eds.), pp. 221-238. Santa Monica, CA: Goodyear Publishing.

Vollmer, August. 1936. The Police and Modern Society: Plain Talk Based on Practical Experience. Berkley, California: University of California Press.

Wilson, James Q. 1968. Varieties of Police Behavior. Cambridge: Harvard University Press.

Young, Malcolm. 1991. An Inside Job: Policing and Police Culture in Britain. Oxford: Clarendon Press.