Homicides involving Black victims are less likely to be cleared in the United States

Does a victim's race explain variation in the likelihood of homicide clearance? Attempts to address this issue date back to the 1970s. Yet, despite its theoretical and policy relevance, we lack a comprehensive and clear empirical answer to this critical question. Here, I causally focus on this problem by investigating racial disparity in homicide clearance in the United States, exploiting two sources covering the 1991–2020 period: the Murder Accountability Project data set (N = 522,278) and the National Incident-Based Reporting System data set (N = 98,677). I primarily analyze these sources by employing exact matching to achieve perfect covariate balance and subsequently isolate the effect of race on the probability of clearance. For comparative purposes, I also use regression adjustment without matching obtaining complementary estimates. I demonstrate that the likelihood of clearance is 3.4 to 4.8 percent lower for homicides involving Black victims, depending on the sampling and estimation approach. In addition, I empirically show that this race effect is slightly higher for males and that racial disparity has moderately but significantly increased over time. These findings contribute to the extensive amount of evidence on discrimination affecting Black individuals in the administration of justice in the United States, calling for structural efforts to reduce this divide.     

Lawlessness in the Federal Sentencing Process: A Test for Uniformity and Consistency in Sentence Outcomes

One of the important goals of the federal sentencing guidelines was to reduce inter‐judge disparity in sentencing. In this paper, we test the assumption that structuring discretion produced uniformity in federal sentencing and consistency in the process by which judges arrive at the appropriate sentence. We also examine whether background characteristics of judges affect the sentences they impose on similarly situated offenders. We used hierarchical linear modeling, nesting the offenders in the judges that sentenced them in order to examine the sentencing decisions of federal judges in three U.S. District Courts. While we found that significant variation between judges in sentencing is largely accounted for by our level 1 characteristics, we also found that judges arrive at decisions regarding the appropriate sentence in different ways, by attaching differential weights to several of the legally relevant case characteristics and legally irrelevant offender characteristics.     

An accuracy assessment of forensic computerized facial reconstruction employing cone-beam computed tomography from live subjects

The utilization of 3D computerized systems has allowed more effective procedures for forensic facial reconstruction. Three 3D computerized facial reconstructions were produced using skull models from live adult Korean subjects to assess facial morphology prediction accuracy. The 3D skeletal and facial data were recorded from the subjects in an upright position using a cone-beam CT scanner. Shell-to-shell deviation maps were created using 3D surface comparison software, and the deviation errors between the reconstructed and target faces were measured. Results showed that 54%, 65%, and 77% of the three facial reconstruction surfaces had <2.5 mm of error when compared to the relevant target face. The average error for each reconstruction was -0.46 mm (SD = 2.81) for A, -0.31 mm (SD = 2.40) for B, and -0.49 mm (SD = 2.16) for C. The facial features of the reconstructions demonstrated good levels of accuracy compared to the target faces.     

GENERATIVE EXPLANATIONS OF CRIME: USING SIMULATION TO TEST CRIMINOLOGICAL THEORY*

This study demonstrates that computational modeling and, in particular, agent‐based modeling (ABM) offers a viable compatriot to traditional experimental methodologies for criminology scholars. ABM can be used as a means to operationalize and test hypothetical mechanisms that offer a potential explanation for commonly observed criminological phenomena. This study tests whether the hypothesized mechanisms of environmental criminology are sufficient to produce several commonly observed characteristics of crime. We present an ABM of residential burglary, simulating a world inhabited by potential targets and offenders who behave according to the theoretical propositions of environmental criminology. A series of simulated experiments examining the impact of these mechanisms on patterns of offending are performed. The outputs of these simulations then are compared with several well‐established findings derived from empirical studies of residential burglary, including the spatial concentration of crime, repeat victimization, and the journey to crime curve. The results from this research demonstrate that the propositions of the routine activity approach, rational choice perspective, and crime pattern theory provide a viable generative explanation for several independent characteristics of crime.     

Risk Terrain Modeling: Brokering Criminological Theory and GIS Methods for Crime Forecasting

The research presented here has two key objectives. The first is to apply risk terrain modeling (RTM) to forecast the crime of shootings. The risk terrain maps that were produced from RTM use a range of contextual information relevant to the opportunity structure of shootings to estimate risks of future shootings as they are distributed throughout a geography. The second objective was to test the predictive power of the risk terrain maps over two six‐month time periods, and to compare them against the predictive ability of retrospective hot spot maps. Results suggest that risk terrains provide a statistically significant forecast of future shootings across a range of cut points and are substantially more accurate than retrospective hot spot mapping. In addition, risk terrain maps produce information that can be operationalized by police administrators easily and efficiently, such as for directing police patrols to coalesced high‐risk areas.     

Race,Ethnicity, Threat,and the Designation of Career Offenders

Florida statutes allow for the application of enhanced sentences to defendants designated as “Career Offenders.” The application of these laws is discretionary and as such, prosecutors seek the designation for a fraction of the defendants who qualify. Utilizing Hierarchical Generalized Linear Modeling, this paper examines whether individual attributes, such as race and ethnicity, impact an individual's likelihood of receiving the Career Offender designation for 13,704 males sentenced to prison between 2002 and 2004. The second-level analysis incorporates county characteristics into the equation and tests whether these predictors have either a direct or a cross-level effect on the relationship. The broad theoretical framework that guides the present research is grounded in the social threat and social control perspective, which argues that minorities on both the individual and aggregate levels may be perceived as threatening in ways that can mobilize or enhance social controls.     

An Experimental Test of Selectorate Theory

This article uses a laboratory experiment to test one of the main predictions of selectorate theory, that is, that democratic leaders invest more resources in public goods than autocratic leaders. The results of the experiment confirm this prediction and further show citizens are better off on average under democratic institutions than autocratic institutions. Meanwhile, autocratic leaders receive higher payoffs than democratic leaders. Additionally, this article attempts to bring domestic politics into international relations experimentation with a focus on how communication may allow democracies to organize more efficiently for war than autocracies. A game theoretical model shows democracies have the potential to organize optimally and use their citizens’ skills to their full advantage while autocracies do not. The results of the experiment reveal some evidence that democracies organize more efficiently than autocracies, but that this increased efficiency did not produce a higher percentage of conflict wins.     

Cognitive Skills,Adolescent Violence,and the Moderating Role of Neighborhood Disadvantage

Numerous studies uncover a link between cognitive skills and adolescent violence. Overlooked is whether the relationship changes at varying levels of neighborhood disadvantage. We examine the issue by contrasting two models that place individual difference in cognitive skill within a social‐structural framework. Using five waves of the 1997 National Longitudinal Survey of Youth and a three‐level hierarchical model, results indicate that cognitive skill is inversely associated with violence and that the relationship is strongest in non‐disadvantaged neighborhoods. However, the cognitive skills–violence relationship is indistinguishable from zero in the most disadvantaged neighborhoods. The findings are therefore consistent with the hypothesis that social expression of developed ability is muted in disadvantaged contexts.     

DISTINGUISHING FACTS AND ARTIFACTS IN GROUP-BASED MODELING*

Group-based methodology (SPGM) has been presented as suitable to test for the existence of subpopulations not directly observable. Several criminological studies have used this methodology, and it is fair to say that typological theorizing has been spurred by its development. In particular, much of the empirical support for Moffitt's taxonomy (1993, 2006) is from studies using SPGM. In a small simulation experiment, I investigate whether SPGM is suitable for such tests, and I examine the extent to which similar trajectories might equally well result from mechanisms suggested by general theories. I conclude that, as it is usually applied, SPGM cannot provide evidence either for or against a taxonomy and that the usual findings can be explained by competing theories. I argue that this result is not only because of the methodology characteristics but also because of the modeling strategy applied.     

数学建模竞赛与公安院校学生职业能力培养

分析公安院校学生参加数学建模竞赛,体会到数学建模与公安院校学生职业综合能力的培养是密不可分的,认真研究如何将数学建模思想和方法融入到公安大教育职业岗位综合能力的培养,得到一些建设性启示。