By Laura Mills, James Freeman, and Verity Truelove

Facebook groups and pages exist that expose the locations of roadside drug testing, potentially undermining police enforcement and enabling punishment avoidance. This study aimed to understand how and why these sites are used, with a focus on Queensland motorists who reported using illicit drugs and/or medical cannabis and used Facebook police location communities. Interviews with 30 participants were conducted. A thematic analysis revealed that participants used police location communities to avoid receiving a charge for driving under the influence of drugs. Upon observation of a relevant roadside drug-testing location on police location communities, participants reported (a) delaying their driving and/or (b) circumventing the operation. Avoidance of roadside drug-testing locations appeared driven by the perception that laws for driving under the influence of drugs were unfair and that a charge for driving under the influence of drugs would negatively impact their life. The findings provide important knowledge regarding police location communities and have implications for how roadside drug testing could be most effectively operated.

Criminal Justice and Behavior, 2024. (online first)

By David Weisburd, Cody W. Telep , Heather Vovak , Taryn Zastrowa , Anthony A. Braga , and Brandon Turchan  

  Can police be trained to treat people in fair and respectful ways, and if so, will this influence evaluations of the police and crime? To answer these questions, we randomly allocated 120 crime hot spots to a procedural justice (PJ) and standard condition (SC) in three cities. Twenty-eight officers were randomly assigned to the conditions. The PJ condition officers received an intensive 5-d training course in the components of PJ (giving voice, showing neutrality, treating people with respect, and evidencing trustworthy motives). We used police self-report surveys to assess whether the training influenced attitudes, systematic social observations to examine impacts on police behavior in the field, and arrests to assess law enforcement actions. We conducted pre and post household surveys to assess resident attitudes toward the police. Impacts on crime were measured using crime incident and citizen-initiated crime call data. The training led to increased knowledge about PJ and more procedurally just behavior in the field as compared with the SC condition. At the same time, PJ officers made many fewer arrests than SC officers. Residents of the PJ hot spots were significantly less likely to perceive police as harassing or using unnecessary force, though we did not find significant differences between the PJ and SC hot spots in perceptions of PJ and police legitimacy. We found a significant relative 14% decline in crime incidents in the PJ hot spots during the experiment.  

Missouri: PNAS, 2022. 6p.

By Ben Struhl, Alexander Gard-Murray

Many American communities are wrestling with how to reform their approach to public safety in the wake of police killings, particularly of Black men. There are many ideas for what the right reforms might be, ranging from minor policy tweaks to wholesale replacement of departments. To help communities as they sort through these ideas, we review real experiences with policing reform, highlighting wherever possible the best scientific evidence on the subject.  

Philadelphia: University of Pennsylvania, Crime and Justice Policy Lab, 2022. 23p.

By Roseanna Sommers, Vanessa K. Bohns

Most police searches today are authorized by citizens' consent, rather than probable cause or reasonable suspicion. The main constitutional limitation on so-called “consent searches” is the voluntariness test: whether a reasonable person would have felt free to refuse the officer's request to conduct the search. We investigate whether this legal inquiry is subject to a systematic bias whereby uninvolved decision-makers overstate the voluntariness of consent and underestimate the psychological pressure individuals feel to comply. We find evidence for a robust bias extending to requests, tasks, and populations that have not been examined previously. Across three pre-registered experiments, we approached participants (“Experiencers”) with intrusive search requests and measured their behavioral compliance and self-reported feelings of psychological freedom. Another group of participants (“Forecasters”) reported whether they would comply if hypothetically placed in the same situation. Study 1 investigated participants' willingness to allow experimenters access to their unlocked personal smartphones in order to read through the search histories on their web browsers—a private sphere where many individuals feel they have something to hide. Results revealed that whereas 27% of Forecasters reported they would permit such a search, 92% of Experiencers complied when asked. Study 2 replicated this underestimation-of-compliance effect when individuals were asked to permit a search of their purses, backpacks, and other bags—traditional searches not eligible for the heightened legal protection extended to digital devices. Study 3 replicated the gap between Forecasters' projections and Experiencers' behavior in a more representative sample, and found it persists even when participants' predictions are incentivized monetarily.

Journal of Empirical Legal Studies, Volume21, Issue1, March 2024, Pages 4-34

By Rafael A. Mangual

After a long period of continuous violent-crime declines throughout the U.S.—spanning from the mid-1990s through the early 2010s—many American cities are now seeing significant increases in violence. Nationally, in 2015 and 2016, murders rose nearly 11% and 8%, respectively. The national homicide rate declined slightly in 2017 and 2018, before ticking upward in 2019. In 2020, the nation saw its largest single-year spike in homicides in at least 100 years—which was followed by another increase in murders in 2021, according to CDC data and FBI estimates. In the last few years, a number of cities have seen murders hit an all-time high. In addition to homicides, the risk of other types of violent victimizations rose significantly, as well. While various analyses estimated a slight decline in homicides for the country in 2022, many American cities still find themselves dealing with levels of violence far higher than they were a decade ago. While violent crime—particularly murder—is the most serious due in large part to its social costs, there have also been worrying increases in crimes such as retail theft, carjacking, and auto theft, as well as in other visible signs of disorder in public spaces (from open-air drug use and public urination to illegal street racing and large-scale looting and riots). Although several contributing factors are likely, this general deterioration in public safety and order was unquestionably preceded and accompanied by a virtually unidirectional shift toward leniency and away from accountability in the policing, prosecutorial, and criminal-justice policy spaces. That shift is evidenced by, among other things, three major trends in enforcement: • A 25% decline in the number of those imprisoned during 2011–2212 • A 15% decline in the number of those held in jail during 2010–2113 • A 26% decline in the number of arrests effected by law-enforcement officers during 2009–1914 Notable contributing factors to the decline in enforcement include: • A sharp uptick in public scrutiny and interventions—in the form of investigations and legal action taken by state attorneys general and the federal Department of Justice—against local law-enforcement agencies • The worsening of an ongoing police recruitment and retention crisis, particularly in large urban departments • The electoral success of the so-called progressive prosecutor movement, which, by 2022, had won seats in 75 jurisdictions, representing more than 72 million U.S. residents • Perhaps most important, the adoption of a slew of criminal-justice and policing reform measures at all levels of government Those who are skeptical of the criminal-justice reform movement have devoted most of their efforts to arguing against the movement’s excesses and explaining why it would be unwise to enact certain measures. Less effort has been devoted to the extremely important task of articulating a positive agenda for regaining what has been lost on the safety and order front. This paper seeks to add to that positive agenda for safety by proposing three model policies that, if adopted, would help, directly and indirectly, stem the tide of rising crime and violence, primarily by maximizing the benefits that attend the incapacitation of serious criminals (especially repeat offenders) and by encouraging the collection and public reporting of data that can inform the public about the downside risks that are glossed over by decarceration and depolicing activists.

New York: Manhattan Institute, 2023. 19p.

By Alexander Landry, James Druckman, and Robb Willer

Recent, high-profile acts of partisan violence have stimulated interest among academics and the general public in the etiology of support for such violence. Here, Landry, Druckman, and Willer report results of an exploratory study that (1) measures support for partisan violence with both abstract items (e.g., general support for partisan violence) and support for more specific acts (e.g., support for a partisan motivated shooting), (2) follows recently established best practices by including attention checks to attenuate response bias, and (3) incorporates measures of a wide range of potential confounders as control variables. Across three data collections (total N = 2,003), including two with nationally representative samples, and tracking seven unique operationalizations of support for the use of violence against out-partisans, they find the most consistent and typically largest relationships with an individual’s reported “need for chaos” (e.g., agreement with statements like: “Sometimes I just feel like destroying beautiful things”) and the extent to which they dehumanize supporters of the opposing party. The researchers speculate this reflects a motivation to use extreme methods (need for chaos) toward one’s political rivals, liberated from the moral restraints that inhibit harming fellow human beings (dehumanization). System justification and social dominance orientation were also both positively related to support for partisan violence, which may reflect partisans’ desire to protect their preferred social order from out-partisans deemed to threaten it. Collectively, these results offer a framework for future research on support for partisan violence, highlighting the role of extreme orientations toward society and rival partisans.

Evanston, IL: Institute for Policy Research,  Northwestern University, 2023. 56p

By Felipe Gonçalves, Elisa Jácome, and Emily Weisburst

How does immigration enforcement affect public safety? Heightened enforcement could reduce crime by deterring and incapacitating immigrant offenders or, alternatively, increase crime by discouraging victims from reporting offenses. The researchers study the U.S. Secure Communities program, which expanded interior enforcement against unauthorized immigrants. Using national survey data, they find that the program reduced the likelihood that Hispanic victims reported crimes to police and increased the victimization of Hispanics. Total reported crimes are unchanged, masking these opposing effects. The researchers provide evidence that reduced Hispanic reporting is the key driver of increased victimization. Their findings underscore the importance of trust in institutions as a central determinant of public safety.

Evanston, IL: Institute for Policy Research,  Northwestern University, 2024. 95p.

By Beth Redbird and Kat Albrecht

Racial disparity in arresting behavior is a significant concern for people of color. It also delegitimizes law enforcement, increases tension between police and citizens, and can even increase crime. Efforts at police reform stall, in part because racial disparity in policing was previously unmeasurable. The authors present three new measures of racial disparity in arrest, measured across more than 13,000 agencies nationwide, allowing for reliable analysis of disparity across time and geographic space. These measures are validated against Department of Justice law enforcement misconduct investigations, the “gold standard” for assessing racial disparity in policing.

Evanston, IL: Institute for Policy Research,  Northwestern University, 2020. 48p.

By Gabrielle T. Isaza,  Robin S. Engel,  Nicholas Corsaro,  M. Murat Ozer

  This report summarizes the details of a problem analysis conducted by the International Association of Chiefs of Police/University of Cincinnati (IACP/UC) Center for Police Research and Policy (the “Center”) on domestic violence patterns for the Tulsa Police Department (TPD). The TPD identified domestic violence as an area requiring further understanding given the seriousness of the crime, and frequency as measured by citizen-generated calls for service. For the TPD, domestic violence-related incidents represent their third most frequent call for service, consuming substantial police resources. Prior to recommending an appropriate intervention strategy to reduce domestic violence, it is critical to better understand details regarding the specific domestic violence problem in Tulsa. For police agencies, a problem analysis includes the systematic examination of the underlying conditions of local problems they are tasked with solving. Problem analyses generally rely on information gathered from various sources, and should include examinations of both qualitative and quantitative data. The problem analysis process is critical for developing solutions that fit the problem in each community, because what works in one jurisdiction may not fit a similar problem in another setting (Boba, 2003). The following study documents a problem analysis based on a series of statistical analyses conducted on five-years of domestic violence data reported to the TPD (2013-2017) and victimization data gathered by the Family Service Center in Tulsa. Domestic violence is defined as an incidence of assault and battery against individuals connected to the suspect by one of fifteen different categories of relationship (see Oklahoma Statute §21-644). These variations in relationships cover both common (e.g. husband-wife or child-parent) and seemingly more distant (e.g. spouse-former spouse of partner or former roommate) relationships between individuals. Unfortunately, the automated data used by the TPD does not include a field for the relationship between the victim and offender. TPD data included reports for incidents, arrests, victims, calls for service, and field interview reports. These analyses were supplemented with domestic victimization data provided from the Family Service Center. The main findings of this problem analysis are summarized below. . Domestic violence-related calls for service were the third most frequent call received by the TPD (n=109,623; preceded by traffic stops and alarms) between 2013 and 2017. These reports were relatively stable over the five-year period, with an average of 21,942 calls per year. . Citizen-generated indicators of domestic violence (i.e. calls for service and incident reports) remained relatively stable over the five-year period, while the TPD-generated responses (i.e. FIR and arrest) to these crimes decreased noticeably over the same period of time. Arrests for domestic violence declined by 40.9% from 2013 to 2017, and FIRS similarly declined by 46.8% from 2013 to 2017.. TPD-generated incident reports indicate that 84.5% (n=13,381) of identified suspects were suspected of only committing one domestic violence offense, whereas 15.5% (n=2,447) were suspected of committing two or more offenses. . TPD-generated victimization reports indicate 83.8% (n=15,564) individuals were victimized once, and 16.2% (n=3,008) were victimized two or more times. . These findings demonstrate that the “repeat phenomenon” of domestic violence victimization in Tulsa is similar between victims and suspects. That is, victims are just as likely to be victimized more than once (16.2%) compared to offenders involved in more than one offense (15.5%). . Victimization data provided by the Family Safety Center indicates large increases in the number of services provided (180.6% increase) and the number of individuals receiving services (118.1% increase), likely due to the expansion of victim-services provided in Tulsa during the five-year study time period. Note that the increase of use of victim services is inconsistent with the downward trend in TPD domestic violence arrests. . Data from the FSC also indicates that the percentage of Black victims receiving FSC services (19.3%) was lower than expected given the victimization data captured by the TPD (31.6% for single incidents and 40.6% for repeat incidents), suggesting that Black domestic violence victims may be less likely to request or to receive services. . Analyses also show that 15.5% (n= 2,447) of the individuals suspected of domestic violence offenses were repeat offenders, and they accounted for 23.2% of the domestic violence incidents reported during the study period. . When offenders did commit a subsequent domestic violence offense for which an arrest occurred, the time between arrests was extremely long (an average of over 500 days). However, as the number of repeat domestic violence offenses increase per an offender, the number of days between these arrests decreases. Nonetheless, the average time between offenses is substantially long, indicating that focused deterrence approaches to repeat domestic violence offenders may not be effective in Tulsa (Sechrist, Weil, and Shelton, 2016).  Police data demonstrate that while a person was a victim in one incident, the same person was also commonly reported as the suspect in another domestic violence incident. Approximately 3,205 unique victims (17.2% of all domestic victims) were also charged as a suspect in a different domestic violence case.  Approximately 15% (8 out of 53) of offenders in domestic violence homicide incidents had a previous arrest for domestic violence.  A review of the relationship between the victim and suspect identified in the field interview reports indicates that the most common relationship type is current spouse/cohabitant (43.3%), followed by former spouse/cohabitant (20.3%), and dating (18.0%). Very few cases involve other types of relationships.  Field interview reports (FIR) revealed a substantial number of cases (36.7%), which involve the suspect threatening a future action—these represent an avenue for follow-up by TPD officer   

Cincinnati: International Association of Chief of Police (IACP) / University of Cincinnati (UC) Center for Police Research and Policy. 2019. 41p.

By John R. "Rick" Brown, Robin S. Engel, et al.

The Colorado Springs Police Department (CSPD) commissioned this report in partnership with the City of Colorado Springs to provide a proactive, independent systematic review of the patterns and trends associated with use of force by the CSPD. In response to Request for Proposal, Consultant Services (R20-093 IP), Assessment of Colorado Springs Police Department’s Use of Force released on July 20, 2020, the Transparency Matters, LLC (hereafter TMLLC) team was selected to complete this work. This report documents the results from comprehensive analyses of use of force incidents reported by the CSPD, specifically focusing on understanding how, when, why, and against whom officers use force, as well as the context of police encounters with the public, from both the community and officer perspectives. The purpose of this study is to examine current practices and identify opportunities to reduce the frequency and severity of use of force incidents, racial/ethnic disparities in force, and injuries to both officers and citizens through improvements to policies, training, and supervision. This report includes nine sections: (1) Introduction, (2) Review of CSPD Policies and Practices, (3) Data and Research Methods, (4) Physical Force and Weapons Used, (5) Types of Force, Force Effectiveness, and Injuries, (6) Pointing of Firearms, (7) Community Perspectives, (8) CSPD Officer Perspectives, and (9) Recommendations. This executive summary provides an overview of the primary findings from each of these report sections. 

Lancaster, PA:Transparency Matters and University of Cincinnati, 2022. 280p

By Nazgol Ghandnoosh and Celeste Barry

As noted in the first installment of this One in Five series, scholars have declared a “generational shift” in the lifetime likelihood of imprisonment for Black men, from a staggering one in three for those born in 1981 to a still troubling one in five for Black men born in 2001. “I can’t breathe,” George Floyd said over 20 times. “Every time you see me, you want to mess with me,” said Eric Garner. “I just want to go home,” said Tyre Nichols. Breonna Taylor asked who had come into her apartment in the middle of the night. Police killed them all. The Black Lives Matter movement has rightly highlighted the tragic deaths resulting from policing’s biased and excessive contact with people of color. Nearly half of those killed by police in recent years have been Black or Latinx, and officers are rarely held accountable. This report interrogates the large footprint of policing—particularly of Black Americans— as, in part, a failed response to racial disparities in serious crimes. The wide net that police cast across people of color is at odds with advancing safety because excessive police contact often fails to intercept serious criminal activity and diminishes the perceived legitimacy of law enforcement. Excessive policing also distracts policymakers from making investments to promote community safety without the harms of policing and incarceration. In addition, the large footprint of policing gets in the way of, as the National Academies of Sciences has called for, needed “durable investments in disadvantaged urban neighborhoods that match the persistent and longstanding nature of institutional disinvestment that such neighborhoods have endured over many years.”

Washington, DC: Sentencing Project, 2023. 27p.

By Julie Berg and Emily Mann

The authors undertook a literature review on intersectionality and policing to provide a critical, impact-based account of scholarly/academic engagement with policing and intersectionality. This review informs an intersectional good practice toolkit by which police organisations can better engage with the phenomenon of intersectionality and its implications for policing and ‘seldom heard communities’. Additionally, the authors hosted two interactive workshops to share preliminary findings, consult with academics and police practitioners and request feedback. The review highlighted that intersectional convergence of certain social identities and characteristics can provide complex challenges for policing, for example: The impact of micro-interactions between the police and those with intersecting social identities. Meso-level institutional issues may mitigate or aggravate negative interactions between the police and those with intersecting identities (such as police culture, resources, specialist training, and/or whether the police have specialist teams or programmes). Macro-level factors; the police operate under broader structural influences and power dynamics which negatively impact on certain groups, and which is informed by both historical and contemporary factors such as law, policy, political and public discourses and expectations.

Edinburgh: Scottish Police Academy, 2023. 71p.

By Grahame Allen, Helena Carthew

Data from the Home Office, Scottish Government, and Police Service of Northern Ireland (PSNI) shows us how large the police workforce is. It also indicates how diverse forces are, including breakdowns by sex and ethnicity. This briefing breaks down data by police force area where possible and includes international comparisons where available.

London: UK Parliament, House of Commons Library, 2024. 32p.

 By The U.S. Department of Justice

On May 24, 2022, a mass shooting at Robb Elementary School in Uvalde, Texas, shook the nation. In the aftermath of the tragedy, there was significant public criticism of the law enforcement response to the shooting. At the request of the then mayor of Uvalde, the U.S. Department of Justice (DOJ) conducted a Critical Incident Review (CIR) of the law enforcement response to the mass shooting. In providing a detailed accounting and critical assessment of the first responder actions in Uvalde, and the efforts since to ameliorate gaps and deficiencies in that response, this report is intended to build on the knowledge base for responding to incidents of mass violence. It also will identify generally accepted practices for an effective law enforcement response to such incidents. Finally, it is intended to help honor the victims and survivors of the Robb Elementary School tragedy. 

Washington, DC: Office of Community Oriented Policing Services, 2024. 610p.

By Institute for Intergovernmental Research

 This publication presents abbreviated case studies of large and small law enforcement agencies that have undergone or are currently conducting change initiatives to address a wide range of pressing issues common to law enforcement, such as backlogged sexual assault cases, lack of community trust, inadequate information and intelligence sharing, and increases in violent or juvenile crime. These issues and others prompted change initiatives among the 13 agencies interviewed for this resource. In September 2022, executives from several of the case study agencies met in Washington, D.C., for a working session to provide additional insights learned through the change experience (see appendix A for a list of roundtable attendees). The experiences of these agencies are documented in this publication with the hope that law enforcement executives and managers will find the strategies, actions, and lessons learned helpful in adapting to changes in their internal and external environments.

Washington, DC: Office of Community Oriented Policing Services. 2023. 60p.

By The New Jersey Office of the State Comptroller

The Office of the State Comptroller (OSC) is authorized to conduct audits, investigations, and reviews of Executive branch entities, including state and local police departments, to identify and prevent fraud, waste, and abuse in the expenditure of public funds. OSC initiated this investigation into Street Cop Training (Street Cop or the Company) after receiving information that public funds were spent to send New Jersey police officers to a six-day conference in October 2021 in Atlantic City that trained officers on questionable policing tactics and contained offensive and discriminatory content (the Conference). Street Cop is a New Jersey-based company. Around 990 law enforcement officers nationwide attended the Conference, with about 240 from New Jersey. The 240 New Jersey officers came from agencies across the state, working at all levels of government—interstate, state, county, and municipal. The majority of these officers had their attendance paid for by their public employers. OSC’s investigation confirmed that at least $75,000 in public funds were directly spent by New Jersey entities on attendance at the Conference. This number does not include paid time off and/or paid training days relating to officers’ attendance. To conduct this investigation, OSC’s Police Accountability Project reviewed documents, videos, and other materials received from the Company, training centers, and various law enforcement agencies and departments with officers in attendance at the Conference, among other sources. OSC also consulted directives, regulations, policies, and case law, and conducted interviews of relevant witnesses. OSC also conducted a sworn interview with Street Cop’s founder and Chief Executive Officer, Dennis Benigno. OSC’s investigation uncovered alarming deficiencies in the police training provided at the Conference and a dangerous and potentially costly gap in the oversight of private post-academy police training. Currently, private post-academy police training in New Jersey is not regulated by the Attorney General, Police Training Commission (PTC), or any other designated entity. Among other things, OSC found: • Instructors at the Conference promoted the use of unconstitutional policing tactics for motor vehicle stops; • Some instructors glorified violence and an excessively militaristic or “warrior” approach to policing. Other presenters spoke disparagingly of the internal affairs process; promoted an “us vs. them” approach; and espoused views and tactics that would undermine almost a decade of police reform efforts in New Jersey, including those aimed at de-escalating civilian-police encounters, building trust with vulnerable populations, and increasing officers’ ability to understand, appreciate, and interact with New Jersey’s diverse population; and • The Conference included over 100 discriminatory and harassing remarks by speakers and instructors, with repeated references to speakers’ genitalia, lewd gestures, and demeaning quips about women and minorities. This kind of training comes at too high a price for New Jersey residents. The costs of attendance for training like this is small in comparison to the potential liability for lawsuits involving excessive force, unlawful searches and seizures, and harassment and discrimination. It is well-documented  that state and local entities in New Jersey spend millions of dollars litigating these types of allegations. Between 2012 and 2018, over 100 excessive force lawsuits were brought against officers and departments in New Jersey. 1 And in 2022, just one excessive force lawsuit cost a New Jersey county $10 million. 2 The costs of lawsuits alleging discrimination or harassment can be just as expensive. By one estimate, from 2019 to 2023, New Jersey police departments agreed to pay at least $87.8 million to resolve claims of misconduct by officers, and many of those claims involved harassing and discriminatory behaviors. 3 Of course, these quantifiable high dollar amounts do not include the immeasurable and hidden cost to the victims, their families, and their communities. Quality police training can play a crucial role in ensuring law enforcement is equipped with the knowledge, expertise, and experience to navigate complex and difficult situations safely. But training that encourages officers to employ techniques that violate civil liberties, disparage legitimate public safety initiatives, undermine police reform efforts, and promote a toxic culture in which women and racial and ethnic minorities are made to feel unwelcome — this is not training that should be paid for with New Jersey’s public money. In light of these findings, and because Street Cop and other private police training companies who receive public funds operate without oversight or regulation by the Attorney General, PTC, or any other designated organization, OSC makes nine recommendations. OSC is also making a number of referrals to appropriate agencies, including to the Attorney General, the Division on Civil Rights, and internal affairs departments for further investigation into OSC’s publicly reported findings, and into additional concerning conduct identified in OSC’s review of the Conference presentations. 

Trenton: New Jersey Office of the State Comptroller, 2023. 43p.

By Chris Bath

Police forces in England and Wales carried out an estimated 145,000 voluntary interviews under caution in 2022/23, of which around one fifth were of children. Only 4.8% of adults attending a voluntary interview were recorded as meeting the criteria for appropriate adult (AA) support – around half the rate in police custody. While custody rightly attracts scrutiny, this report highlights both why and how a strategic focus should be brought to bear on voluntary interviews. Part 1 presents an analysis of quantitative data provided by police forces. Part 2 sets out the policy and practice challenges from the perspective of local appropriate adult scheme leaders.   

Ashford, Kent, UK: National Appropriate Adult Network , 2023. 29p.  

By Jeffrey Fagan and Lila Nojima

Theories of rational behavior assume that actors make decisions where the benefits of their acts exceed their costs or losses. If those expected costs and benefits change over time, the behavior will change accordingly as actors learn and internalize the parameters of success and failure. In the context of proactive policing, police stops that achieve any of several goals—constitutional compliance, stops that lead to “good” arrests or summonses, stops that lead to seizures of weapons, drugs, or other contraband, or stops that produce good will and citizen cooperation—should signal to officers the features of a stop that increase its rewards or benefits. Having formed a subjective estimate of success (i.e., prior beliefs), officers should observe their outcomes in subsequent encounters and form updated probability estimates, with specific features of the event, with a positive weight on those features. Officers should also learn the features of unproductive stops and adjust accordingly. A rational actor would pursue “good” or “productive” stops and avoid “unproductive” stops by updating their knowledge of these features through experience. We analyze data on 4.9 million Terry stops in New York City from 2004–2016 to estimate the extent of updating by officers in the New York Police Department. We compare models using a frequentist analysis of officer behavior with a Bayesian analysis where subsequent events are weighted by the signals from prior events. By comparing productive and unproductive stops, the analysis estimates the weights or values—an experience effect—that officers assign to the signals of each type of stop outcome. We find evidence of updating using both analytic methods, although the “hit rates”—our measure of stop productivity including recovery of firearms or arrests for criminal behavior—remain low. Updating is independent of total officer stop activity each month, suggesting that learning may be selective and specific to certain stop features. However, hit rates decline as officer stop activity increases. Both updating and hit rates improved as stop rates declined following a series of internal memoranda and trial orders beginning in May 2012. There is also evidence of differential updating by officers conditional on a variety of features of prior and current stops, including suspect race and stop legality. Though our analysis is limited to NYPD stops, given the ubiquity of policing regimes of intensive stop and frisk encounters across the United States, the relevance of these findings reaches beyond New York City. These regimes reveal tensions between the Terry jurisprudence of reasonable suspicion and evidence on contemporary police practices across the country.

New York, NY: Columbia Public Law School, 2023, 61p.

By Kasey Henricks and Ruben Ortiz

The Irrelevance of Innocence” is a case study of Chicago that focuses on parking tickets that are written under false pretenses. We leverage multiple data sets against one another to demonstrate that more than one in eight tickets over a six-year span were written under conditions when restrictions did not apply. Then, we situate these findings within a multilevel framework to answer three questions: (1) Are errored tickets more likely to be issued in neighborhoods with higher proportions of Black or Latinx residents? (2) Are errored tickets more likely to be issued by patrol officers as opposed to parking enforcement officers? and (3) Does ethnoracial composition moderate the relationship between ticketing authorities and errored tickets? The implications of our findings (1) quantitatively trouble the ontological assumptions of data that are defined from a policing standpoint and (2) underscore an adjudicative process that routinely sanctions drivers without cause.

Socius: Sociological Research for a Dynamic World, March 2023. 19p.

By Manja Nikolovska, Shane D. Johnson and Paul Ekblom

Crisis and disruption are often unpredictable and can create opportunities for crime. During such times, policing may also need to meet additional challenges to handle the disruption. The use of social media by officials can be essential for crisis mitigation and crime reduction. In this paper, we study the use of Twitter for crime mitigation and reduction by UK police (and associated) agencies in the early stages of the Covid-19 pandemic. Our findings suggest that whilst most of the tweets from our sample concerned issues that were not specifically about crime, especially during the first stages of the pandemic, there was a significant increase in tweets about fraud, cybercrime and domestic abuse. There was also an increase in retweeting activity as opposed to the creation of original messages. Moreover, in terms of the impact of tweets, as measured by the rate at which they are retweeted, followers were more likely to ‘spread the word’ when the tweet was content-rich (discussed a crime specific matter and contained media), and account holders were themselves more active on Twitter. Considering the changing world we live in, criminal opportunity is likely to evolve. To help mitigate this, policy makers and researchers should consider more systematic approaches to developing social media communication strategies for the purpose of crime mitigation and reduction during disruption and change more generally. We suggest a framework for so doing.

Crime Science 2020 9:20