Illegal Data
The relative and joint effects of gunshot detection technology and video surveillance cameras on case clearance in Chicago
Eric Piza et al.
Criminology & Public Policy, forthcoming
Abstract:
Closed-circuit television (CCTV) video surveillance cameras and gunshot detection technology (GDT) have been widely adopted by police departments in recent years. Most evaluation research on CCTV and GDT has tested the technologies’ effect on crime prevention rather than case clearance rates. The current study contributes to the literature through a matched quasi-experiment of the relative and joint effect of GDT and CCTV on fatal and nonfatal shooting investigation outcomes in Chicago, IL. Entropy balancing is used to create a weighted control group that closely resembles the treatment group. Logistic regression models incorporating the weights from the entropy matching procedure as probability weights measure the intervention effects. Treatment conditions generated null findings across all models. Although included as a control variable in the models, Chicago's Strategic Decision Support Centers (SDSCs) were positively associated with case clearance in the nonfatal shooting models.
Judicial Decisions on Electronic Control Devices and Police Escalation of Force
Courtenay Monroe, Sophia Hatz & Kristine Eck
Journal of Politics, forthcoming
Abstract:
Jurisprudence regarding whether police use of electronic control devices (ECDs) constitutes excessive use of force varies substantially across US states and over time. In this letter, we investigate the extent to which year-to-year switches in US Courts of Appeals decisions lead to escalations in police use of force. Using a generalized difference-in-difference design, we show that switches in judicial restrictiveness regarding the legal use of ECDs are associated with an increase in the use of lethal force as measured by the number of civilians shot and killed by police officers.
A Novel Method for Measuring the Extent of Cocaine Flows Across the U.S.
Siddharth Chandra et al.
Justice Quarterly, forthcoming
Abstract:
We propose a novel method to measure the spatial extent of cocaine flows in the US using data on the price and purity of cocaine observed in drug seizures or undercover drug purchases. We then compare the cocaine trafficking network extracted using this method to anecdotal knowledge about cocaine flows using network analytic methods. Based on the network analysis, the trafficking networks inferred from price and purity data appear to be more elaborate in their geographic extent than prior anecdotal evidence suggests. The analysis uncovers previously unrecognized flows, notably identifying multiple possible cocaine source points along the US-Canadian border, challenging the traditional and likely incomplete narrative focused on the southern border. This study demonstrates that variation in cocaine purity across space and over time can help detect unconventional patterns of cocaine flows, complementing the conventional understanding of the extent of cocaine flows.
The Classroom and the Yard: The Contrasting Context of Prison Higher Education and Its Role in Racial Bias Mitigation
Meredith Sadin, Amy Lerman & Ben Fils
Law & Social Inquiry, forthcoming
Abstract:
Prison has long been recognized as a racialized institution in America, where race determines myriad aspects of life -- from where individuals sleep to those with whom they live, eat, and socialize during incarceration. However, there is little evidence on how to effectively remediate prisons’ deep racial divisions—a question that is imperative given that interracial animus in prisons can be both a result and a determinant of racial conflict and violence. In this study, we argue that higher education in prison has significant potential to improve racial attitudes and foster racial integration by providing a “contrasting context” for interracial interaction in the classroom within an otherwise racially segregated institution. Using administrative data on college-level course completion, an original longitudinal survey of prison college students, and in-depth qualitative interviews with prison college alumni, we show evidence of shifts in racial attitudes and self-reported behavior as students move through their college career. Our results demonstrate the potential for prison higher education to shift race-based norms and offer a framework through which to analyze prison education that prioritizes outcomes of interest beyond recidivism.
Sources of organizational variability in fatal police shootings in the USA
Roland Neil, John MacDonald & Anthony Braga
Nature Human Behaviour, June 2025, Pages 1113-1121
Abstract:
The rate of fatal shootings by officers is highly variable across American police agencies, yet the reasons for this variability remain unclear. This study uses Bayesian multilevel models to partition the variation in fatal police shooting rates across 2,727 police agencies between 2015 and 2020 into 3 sources of variability: randomness, differences in social context, and outlier agencies that have exceptionally higher or lower rates than is predicted by observed factors. The results indicate that variation in police shooting rates across agencies is far from random and is primarily associated with differences in social contexts, especially differences in crime rates, 911 call rates, officers per capita and the prevalence of guns. However, even after accounting for extensive differences in contexts, several police agencies consistently have lower or higher police shooting rates than predicted.
The Influence of Workplace Friendships on Police Firearm Use
Marie Ouellet et al.
Justice Quarterly, forthcoming
Abstract:
Early police ethnographies suggest that officers are shaped by the colleagues around them. A common observation is that Officers’ workplace networks, including friendships and routine, day-to-day interactions are theorized to serve as key channels through which behaviors such as use of force spread. Yet few studies have directly traced the how these networks transmit force-related behaviors. To address this gap, we mapped the workplace friendship ties of more than 1,500 officers in a large US police department. We then asked whether officers’ firearm use is shaped by the colleagues they consider close friends. Longitudinal network models show that officers tend to adopt similar levels of firearm use to that of their workplace friends, even when accounting for individual characteristics and situational variables. These findings indicate that firearm behavior is shaped not only by personal attributes and work environments, but also by officers’ friendships.
Revisiting the Lasting Impacts of Incarceration
John Eric Humphries et al.
University of Virginia Working Paper, June 2025
Abstract:
Using newly-linked administrative and commercial data from Virginia spanning 25 years, we study the consequences of incarceration. While previous research has examined labor market outcomes and recidivism, we focus on two of the primary channels through which low-income households build wealth: asset ownership (homes and cars) and human capital formation. To identify causal effects, we use a matched difference-in-differences design. In line with much of the literature on the impact of incarceration in the U.S., we find no evidence of scarring effects on labor market outcomes or changes in recidivism beyond the incapacitation period. However, we find that incarceration leads to a persistent reduction in asset accumulation: seven years after sentencing, homeownership has declined by 1.1 percentage points (12.1%) and car ownership by 2.7 percentage points (18.1%). Incarceration also lowers human capital formation, reducing college enrollment by 1.4 percentage points (15.1%).
Financial Incentives and Public Safety: The Role of Blood Plasma Donation Centers in Crime Reduction
Sam Kang, Brendon McConnell & Mariyana Zapryanova
Smith College Working Paper, May 2025
Abstract:
The United States is one of the few OECD countries to pay individuals to donate blood plasma and is the most generous in terms of remuneration. The opening of a local blood plasma center represents a positive, prospective income shock for would-be donors. Using detailed data on the location of blood plasma centers in the US and two complementary difference-in-differences research designs, we study the impact of these centers on crime outcomes. Our findings indicate that the opening of a plasma center in a city leads to a 12% drop in the crime rate, an effect driven primarily by property and drug-related offenses. A within-city design confirms these findings, highlighting large crime drops in neighborhoods close to a newly opened plasma center. The crime-reducing effects of plasma donation income are particularly pronounced in less affluent areas, underscoring the financial channel as the primary mechanism behind these results. This study further posits that the perceived severity of plasma center sanctions against substance use, combined with the financial channel, significantly contributes to the observed decline in drug possession incidents.
Drug trafficking and the homicide epidemic in the Caribbean Basin
Brian Marein
Wake Forest University Working Paper, April 2025
Abstract:
Most of the world’s highest homicide rates are found in the Caribbean basin. Common explanations for the region’s violence -- such as inequality and long-standing
Culture -- fail to explain the explosive growth of violence in recent decades. This paper examines the role of drug trafficking, a leading explanation among law enforcement but one that is difficult to establish causally due to the illicit and covert nature of the trade. I leverage an exogenous shock to drug trafficking: the 1973 Chilean coup, which abruptly redirected trafficking routes northward to Colombia and through the Caribbean. Using Puerto Rico, the Caribbean territory with the best data coverage, and a synthetic control constructed from US states -- which share federal gun laws and other policies affecting violence -- I estimate that the shock caused a 50% increase in homicides. Evidence from other parts of the region supports drug trafficking as the key driver of the Caribbean’s extraordinarily high levels of violence.
Pre-interview hypothesis generation: Large language models (LLMs) show promise for child abuse investigations
Liisa Järvilehto et al.
Psychology, Crime & Law, forthcoming
Abstract:
Investigative interviews in child abuse (CA) cases are vulnerable to biases that can compromise the investigation's objectivity. Children's initial statements are often ambiguous or incomplete due to developmental and motivational factors, leaving room for adult interpretations and suggestive influences. These biases need to be minimized, particularly before the investigative interview, which is often the primary evidence. Although there is a recognized need for formulating case-specific hypotheses to guide interviews, practical guidance is limited. We compared the capabilities of Large Language Models (LLMs) and humans with varying expertise levels in generating pre-interview hypotheses. Participants included CA investigation experts (n = 21), psychologists (n = 60), naive participants (n = 60), and two LLMs (GPT-4 Turbo and Llama 2). Each human group generated hypotheses for four of eight case vignettes, while LLMs generated hypotheses for all eight. This resulted in 81 sets from experts, 240 sets from other human groups, and 480 sets from LLMs. Hypotheses were evaluated for testability, specificity, and comprehensiveness. GPT-4 outperformed humans in generating a higher number of hypotheses that were also more specific and comprehensive. This highlights the potential of LLMs to assist in hypothesis formulation, suggesting they can enhance the objectivity and thoroughness of CA investigations.