Reforming the police through procedural justice training: A multicity randomized trial at crime hot spots.

SignificanceOur study is a randomized trial in policing confirming that intensive training in procedural justice (PJ) can lead to more procedurally just behavior and less disrespectful treatment of people at high-crime places. The fact that the PJ intervention reduced arrests by police officers, positively influenced residents' perceptions of police harassment and violence, and also reduced crime provides important guidance for police reform in a period of strong criticism of policing. This randomized trial points to the potential for PJ training not simply to encourage fair and respectful policing but also to improve evaluations of the police and crime prevention effectiveness.

Population-level effects on crime of recovering firearms from armed prohibited persons: intention-to-treat analysis of a pragmatic cluster-randomised trial in California cities.

BACKGROUND: Too little is known about the effectiveness of efforts to prevent firearm violence. We evaluated California's Armed and Prohibited Persons System (APPS), which identifies legal purchasers of firearms who have become prohibited persons and seeks to recover all firearms and ammunition to which they have access. DESIGN AND METHODS: This cluster-randomised pragmatic trial was made possible by APPS's expansion from a small pilot to a continuing statewide programme. We included 363 California cities, allocated to early (n=187) or later (n=176) intervention in blocks stratified by region within the state, and within region by population and violent crime rate. The study period began 1 February 2015; region-specific end dates ranged from 1 May 2015 to 1 February 2016. Analysis was on an intention-to-treat, difference-in-difference basis using generalised linear mixed models and generalised estimating equations with robust SEs. The population-level primary outcome measures were monthly city-level counts of firearm-related homicides, robberies and aggravated assaults. The primary model was adjusted for stratification variables; city-level population, population density, socioeconomic status and firearm purchasing; year; and month. FINDINGS: Allocation groups were well balanced on baseline characteristics and implementation measures. In adjusted models, allocation to early intervention was not associated with statistically significant differences in any primary outcome measure; these findings were robust to multiple sensitivity analyses. There was some heterogeneity across regions. CONCLUSIONS: The APPS intervention directly affects a very small percentage of the population, limiting its potential for population-level effects. Individual-level analyses may provide a better estimate of the intervention's effectiveness. TRIAL REGISTRATION NUMBER: NCT02318732.

Privately manufactured firearms, newly purchased firearms, and the rise of urban gun violence.

Gun violence in many U.S. cities increased dramatically after the commencement of the COVID-19 pandemic. Surges in criminal access to untraceable privately manufactured firearms and new guns purchased from licensed dealers have been suggested as risk factors associated with the pandemic increase in gun violence. Official data on 4593 guns recovered in Oakland, California between 2017 and 2021 that were submitted to ATF for subsequent tracing are analyzed to determine whether the sources of crime guns changed and whether privately manufactured firearms and fast time-to-crime traced guns were more likely to be used in violent crime during this time period. Descriptive statistics are used to summarize the characteristics of firearms recovered during the study period and the results of ATF tracing. Logistic regression models are then used to assess systematic differences between firearms recovered during the pre-pandemic years as compared to firearms recovered during the pandemic years, and determine whether certain firearms are more likely to be recovered in violent crime. These analyses estimated large increases during the pandemic in the odds that recovered firearms were privately manufactured and recently purchased. Recovered privately manufactured firearms were also more likely to be associated with violent crimes. These findings support recent efforts to regulate privately manufactured firearms and continued efforts to reduce the illegal diversion of firearms from lawful commerce.

Underground Gun Markets and the Flow of Illegal Guns into the Bronx and Brooklyn: A Mixed Methods Analysis.

New York City (NYC) has experienced large reductions in violent crime over the last two decades, but gun-related violence continues to pose a threat to public safety. Despite strong gun laws, high-risk individuals in NYC neighborhoods are unfortunately still able to access and misuse firearms. This research analyzes NYC's underground gun market by closely examining the flow of guns into the two boroughs where gun violence and crime gun recoveries are most prevalent: the Bronx and Brooklyn. A mixed methods approach is utilized that consists of an assessment of firearms trace data and in-depth interviews with individuals considered to be at high risk for involvement in gun violence. Findings suggest that guns recovered in the Bronx and Brooklyn were significantly more likely to originate in states with less restrictive gun laws and more likely to have changed ownership in unregulated transactions relative to guns recovered elsewhere in NYC. Interviews revealed three primary avenues for illegal guns reaching Bronx and Brooklyn neighborhoods: high-volume gun brokers, middlemen, and individuals who make episodic low-level acquisitions from straw purchasers in other states. No subjects identified theft as a meaningful source of crime guns.

Armed and prohibited: characteristics of unlawful owners of legally purchased firearms.

BACKGROUND: A substantial proportion of individuals who lawfully purchase firearms later become unlawful owners ('prohibited firearm owners'), usually following events associated with an increased risk for future violence. This high-risk population has not previously been described. We aimed to characterise all individuals in California's Armed and Prohibited Persons System (APPS), a statewide programme for recovering firearms from individuals who legally purchased them and later became prohibited from ownership. METHODS: We used univariate and bivariate statistics to describe and compare prohibited firearm owners in APPS with a random sample of non-prohibited firearm owners in relation to age, sex, race/ethnicity and type of firearms owned as of 1 February 2015. We also characterised the geographical distribution of prohibited firearm owners and described their prohibitions. RESULTS: Of the 18 976 prohibited firearm owners, most were men (93%), half were white (53%) and the mean age was 47 years. Prohibited firearm owners were more likely to be male and to be black or Hispanic people than non-prohibited owners. Both prohibited and non-prohibited firearm owners had an average of 2.6 firearms, mostly handguns. Nearly half (48%) of prohibited firearm owners had a felony conviction. Extrapolating from our findings, we estimated that there are approximately 100 000 persons in the USA who unlawfully maintained ownership of their firearms following a felony conviction. CONCLUSIONS: Retention of firearms among persons who become lawfully prohibited from possessing them is common in California. Given the nationwide dearth of a programme to recover such weapons, this is likely true in other states as well.

Closer to Guns: the Role of Street Gangs in Facilitating Access to Illegal Firearms.

Criminal offenders often turn to social networks to gain access to firearms, yet we know little about how networks facilitate access to firearms. This study conducts a network analysis of a co-offending network for the City of Chicago to determine how close any offender may be to a firearm. We use arrest data to recreate the co-offending network of all individuals who were arrested with at least one other person over an eight-year period. We then use data on guns recovered by the police to measure potential network pathways of any individual to known firearms. We test the hypothesis that gangs facilitate access to firearms and the extent to which such access relates to gunshot injury among gang members. Findings reveal that gang membership reduces the potential network distance (how close someone is) to known firearms by 20% or more, and regression results indicate that the closer gang members are to guns, the greater their risk of gunshot victimization.

Evaluation of California's Armed and Prohibited Persons System: study protocol for a cluster-randomised trial.

BACKGROUND AND OBJECTIVE: Too little is known about the effectiveness of efforts to prevent firearm violence. Our objective is to evaluate California's Armed and Prohibited Persons System (APPS), a law enforcement intervention that seeks to recover firearms from individuals who purchased them legally but subsequently became prohibited from having access to firearms. Prohibitions usually arise from events suggesting an increased risk for future violence. DESIGN AND STUDY POPULATION: This group-randomised trial involves approximately 20 000 APPS-eligible individuals in 1041 communities. Randomisation was performed at the community level, to early or later intervention (Group 1 and Group 2, respectively) with stratification by region, population and violent crime rate. METHODS: APPS is being implemented by the California Department of Justice. The principal outcome measure is the incidence of arrest for a firearm-related or violent crime. Primary analysis will be on an intention-to-treat basis, comparing individuals in Group 1 and Group 2 communities. Analyses will focus on time to event, using proportional hazards regression with adjustment for the clustered nature of the data and incorporating individual- and community-level characteristics. Secondary analyses will examine the effect of the intervention on an as treated basis, effects on subgroups, and effects on community-wide measures such as crime rates. DISCUSSION: APPS may have a significant impact on risk for future violence among members of its target population. The findings of this study will likely be generalisable and have clear implications for violence prevention policy and practice. TRIAL REGISTRATION NUMBER: NCT02318732.

The Transmission of Gun and Other Weapon-Involved Violence Within Social Networks.

Fatal and nonfatal injuries resulting from gun violence remain a persistent problem in the United States. The available research suggests that gun violence diffuses among people and across places through social relationships. Understanding the relationship between gun violence within social networks and individual gun violence risk is critical in preventing the spread of gun violence within populations. This systematic review examines the existing scientific evidence on the transmission of gun and other weapon-related violence in household, intimate partner, peer, and co-offending networks. Our review identified 16 studies published between 1996 and 2015 that suggest that exposure to a victim or perpetrator of violence in one's interpersonal relationships and social networks increases the risk of individual victimization and perpetration. Formal network analyses find high concentrations of gun violence in small networks and that exposure to gun violence in one's networks is highly correlated with one's own probability of being a gunshot victim. Physical violence by parents and weapon use by intimate partners also increase risk for victimization and perpetration. Additional work is needed to better characterize the mechanisms through which network exposures increase individual risk for violence and to evaluate interventions aimed at disrupting the spread of gun and other weapon violence in high-risk social networks.

Focused deterrence and the prevention of violent gun injuries: practice, theoretical principles, and scientific evidence.

Focused deterrence strategies are a relatively new addition to a growing portfolio of evidence-based violent gun injury prevention practices available to policy makers and practitioners. These strategies seek to change offender behavior by understanding the underlying violence-producing dynamics and conditions that sustain recurring violent gun injury problems and by implementing a blended strategy of law enforcement, community mobilization, and social service actions. Consistent with documented public health practice, the focused deterrence approach identifies underlying risk factors and causes of recurring violent gun injury problems, develops tailored responses to these underlying conditions, and measures the impact of implemented interventions. This article reviews the practice, theoretical principles, and evaluation evidence on focused deterrence strategies. Although more rigorous randomized studies are needed, the available empirical evidence suggests that these strategies generate noteworthy gun violence reduction impacts and should be part of a broader portfolio of violence prevention strategies available to policy makers and practitioners.

Strong gun laws are not enough: the need for improved enforcement of secondhand gun transfer laws in Massachusetts.

OBJECTIVE: Research suggests that an overwhelming majority of crime guns were transferred by private sellers before recovery by law enforcement. Unfortunately, most states do not regulate these transactions. This study examines whether analyses of state-level private transfer data could be used to develop interventions to reduce the supply of handguns to violent criminals. METHODS: Traced Boston crime handguns first sold at Massachusetts license dealers were matched to state secondhand gun transfer data. Logistic regression and descriptive statistics were used to analyze the characteristics of recovered crime guns and in-state primary and secondary market transaction patterns. RESULTS: For crime handguns with records of secondary market transactions in Massachusetts, many rapidly move from private transfer to recovery by the police. Unfortunately, important transaction data on the in-state sources of nearly 63% of recovered handguns were not readily available to law enforcement agencies. CONCLUSIONS: Data on private transfers of guns could be used to prevent violent injuries by reducing criminal access. However, the passage of strong private transfer gun laws needs to be accompanied by investments in the vigorous enforcement of reporting requirements.

Impact of California firearms sales laws and dealer regulations on the illegal diversion of guns.

OBJECTIVE: The available evidence suggests that more restrictive state firearm sales laws can reduce criminal access to guns. California has firearm-related laws that are more stringent than many other states and regulates its retail firearms dealers to a unique degree. This research seeks to examine the effect of more restrictive state gun laws and regulations on the illegal diversion of guns to criminals. DESIGN: Survival analyses are used to determine whether state firearm sales laws, particularly California's legal context and regulatory regime, impact the distribution of time-to-crime of recovered firearms in that state relative to other US states. SETTING: USA. SUBJECTS: 225,392 traced firearms, where the first retail purchasers and the gun possessors were different individuals, recovered by law enforcement agencies between 2003 and 2006. RESULTS: The increased stringency of state-level firearms laws and regulations leads to consistently older firearms being recovered. California was associated with the oldest recovered crime guns compared with guns associated with other states. These patterns persisted regardless of whether firearms were first purchased within the recovery state or in another state. CONCLUSIONS: These findings suggest that more restrictive gun sales laws and gun dealer regulations do make it more difficult for criminals to acquire new guns first purchased at retail outlets.

Ghost guns and crime: a tale of two California cities.

BACKGROUND: Privately made firearms (PMFs) or "ghost guns" are homemade, unserialized, untraceable firearms that have been increasingly used in violent crime in the United States. Very little is known about the types of PMFs recovered by law enforcement agencies and the crimes associated with these recoveries. This lack of information limits effective violence prevention policies and practices. Comparative analysis of PMF recoveries in specific cities helps clarify whether local PMF patterns and characteristics vary or reflect more general trends. This research advances epidemiological understanding of emergent violent gun injury prevention challenges by identifying variations in recovered PMF types and use in violent, drug, and weapon-related offenses in Los Angeles and San Diego, California. METHODS: Conjunctive analysis of case configurations (CACC) identifies patterns among observations (i.e., case configurations) and calculates their probability associated with a given outcome. CACC was used to identify the most common types of PMFs recovered by the Los Angeles (LAPD) and San Diego (SDPD) police departments. For each department and offense type, case configurations with above-average probabilities of offense involvement were determined. Comparisons across departments were made to identify similarities and differences in PMF characteristics and usage. RESULTS: PMFs were more likely to be involved in violent and weapon-related offenses in Los Angles but more likely to be involved in drug-related offenses in San Diego. In both cities, the 9 mm Polymer 80 handgun was the dominant PMF. However, 9 mm handguns were most likely to be involved in weapon-related offenses in Los Angeles compared to 0.40 handguns in San Diego. Furthermore, large-caliber handguns tended to display above-average probabilities of involvement in violent and drug offenses in Los Angeles. Long guns were represented in case configurations with above-average probabilities of involvement in substantive crimes, including violence. CONCLUSIONS: Comparative analyses of PMF recovery patterns in Los Angeles and San Diego reveal meaningful contextual variations in PMF characteristics and suggest intentional firearm type selections by offenders. The results support increased regulation of PMFs and highlight the importance of efforts to identify and disrupt the illicit supply of large-caliber PMF handguns and PMF long guns.

The geography of violence, alcohol outlets, and drug arrests in Boston.

OBJECTIVES: We examined the relationship between alcohol outlets, drug markets (approximated by arrests for possession and trafficking), and violence in Boston, Massachusetts, in 2006. We analyzed geographic and environmental versus individual factors related to violence and identified areas high in violent crime. METHODS: We used data from the Boston Police Department, US Census, and Massachusetts State Alcohol Beverage Control Commission. Spatial modeling was employed at the block group level, and violent crime, alcohol outlets, and drug markets were mapped. RESULTS: Relative to other block groups, block groups in the highest decile of violent crime (n = 55) were found to be poorer (e.g., lower incomes, higher percentages of vacant homes), and they had greater numbers of alcohol outlets and higher drug arrest rates. Alcohol outlets and drug possession and trafficking arrests were predictive of violent crime. Also, spatial effects resulting from neighboring block groups were related to violent crime. Both alcohol outlet density and type were associated with violent crime in a differentiated and complex way. CONCLUSIONS: With drug possession and trafficking arrests as a proxy for drug markets, spatial relationships between alcohol outlets and violence were found in addition to typical sociodemographic predictors.

The salience of social context, opioid antagonist use, and prior opioid exposure as determinants of fatal and non-fatal opioid overdoses.

This study examines the salience of social context for opioid overdoses in Boston from 2014 to 2019. Longitudinal negative binomial models with random effects indicated that higher levels of concentrated disadvantage, residential instability, and illicit drug activity increased annual block group counts of opioid overdoses. Logistic hierarchical and cross-classified random effects models indicated that the use of Narcan and greater exposure to drugs through previous opioid overdose and contextual lillicit drug crime activity reduced the odds of fatal opioid overdose relative to non-fatal opioid overdose. The findings suggest that the accurate tracking of both fatal and non-fatal overdoses, and a consideration of the broader social context, can facilitate effective public health resource allocation to reduce opioid overdoses.

Social networks and the risk of gunshot injury.

Direct and indirect exposure to gun violence have considerable consequences on individual health and well-being. However, no study has considered the effects of one's social network on gunshot injury. This study investigates the relationship between an individual's position in a high-risk social network and the probability of being a victim of a fatal or non-fatal gunshot wound by combining observational data from the police with records of fatal and non-fatal gunshot injuries among 763 individuals in Boston's Cape Verdean community. A logistic regression approach is used to analyze the probability of being the victim of a fatal or non-fatal gunshot wound and whether such injury is related to age, gender, race, prior criminal activity, exposure to street gangs and other gunshot victims, density of one's peer network, and the social distance to other gunshot victims. The findings demonstrate that 85 % all of the gunshot injuries in the sample occur within a single social network. Probability of gunshot victimization is related to one's network distance to other gunshot victims: each network association removed from another gunshot victim reduces the odds of gunshot victimization by 25 % (odds ratio = 0.75; 95 % confidence interval, 0.65 to 0.87). This indirect exposure to gunshot victimization exerts an effect above and beyond the saturation of gunshot victimization in one's peer network, age, prior criminal activity, and other individual and network variables.

Interpreting the empirical evidence on illegal gun market dynamics.

Thousands of Americans are killed by gunfire each year, and hundreds of thousands more are injured or threatened with guns in robberies and assaults. The burden of gun violence in urban areas is particularly high. Critics suggest that the results of firearm trace data and gun trafficking investigation studies cannot be used to understand the illegal supply of guns to criminals and, therefore, that regulatory and enforcement efforts designed to disrupt illegal firearms markets are futile in addressing criminal access to firearms. In this paper, we present new data to address three key arguments used by skeptics to undermine research on illegal gun market dynamics. We find that criminals rely upon a diverse set of illegal diversion pathways to acquire guns, gun traffickers usually divert small numbers of guns, newer guns are diverted through close-to-retail diversions from legal firearms commerce, and that a diverse set of gun trafficking indicators are needed to identify and shut down gun trafficking pathways.

Opportunities for state-level action to reduce firearm violence: proceeding from the evidence.

Firearm violence remains an important problem, and a large body of evidence shows that guns used in crime follow generally predictable paths from manufacturer to criminal end user. Policy initiatives based on that evidence have been shown to be effective. A recently published study conducted by a leading policy organization presents new evidence and makes specific recommendations for action by state-level policymakers. Unfortunately, the study's analysis is overly simplified, and the recommendations are therefore misleading. We suggest alternatives that are evidence based.

Gun shows and gun violence: fatally flawed study yields misleading results.

A widely publicized but unpublished study of the relationship between gun shows and gun violence is being cited in debates about the regulation of gun shows and gun commerce. We believe the study is fatally flawed. A working paper entitled "The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas" outlined this study, which found no association between gun shows and gun-related deaths. We believe the study reflects a limited understanding of gun shows and gun markets and is not statistically powered to detect even an implausibly large effect of gun shows on gun violence. In addition, the research contains serious ascertainment and classification errors, produces results that are sensitive to minor specification changes in key variables and in some cases have no face validity, and is contradicted by 1 of its own authors' prior research. The study should not be used as evidence in formulating gun policy.

The influence of firearms trafficking on gunshot injuries in a co-offending network.

Individuals at the greatest risk of gunshot victimization are often prohibited from legally acquiring guns in the U.S. due to prior felony convictions or other disqualifications. Prohibited persons often rely on others - such as friends, family members, fellow gang members, and gun brokers - to acquire firearms. This study examines whether the sources of guns recovered from high-risk individuals differ relative to the sources of guns recovered more generally in a major U.S. city, and whether illegally-diverted guns are associated with increased gunshot victimization risk. Using official data, we recreate the co-offending network of individuals in Boston who were arrested or contacted by the police with at least one other person between 2007 and 2014. Firearms trace data are then used to develop measures of the shortest distance between individuals and firearms in their immediate network. Results suggest guns with markers of illegal diversion are more likely to be recovered in the highest risk sector of the network and that the probability of gunshot victimization increases with decreased distance to an individual linked to firearms with markers of illegal trafficking.

Hot spots policing of small geographic areas effects on crime.

Background: In recent years, crime scholars and practitioners have pointed to the potential benefits of focusing crime prevention efforts on crime places. A number of studies suggest that there is significant clustering of crime in small places, or "hot spots," that generate half of all criminal events. Researchers have argued that many crime problems can be reduced more efficiently if police officers focused their attention to these deviant places. The appeal of focusing limited resources on a small number of high-activity crime places is straightforward. If crime can be prevented at these hot spots, then citywide crime totals could be reduced. Objectives: To assess the effects of focused police crime prevention interventions at crime hot spots. The review also examined whether focused police actions at specific locations result in crime displacement (i.e., crime moving around the corner) or diffusion (i.e., crime reduction in surrounding areas) of crime control benefits. Search Methods: A keyword search was performed on 15 abstract databases. Bibliographies of past narrative and empirical reviews of literature that examined the effectiveness of police crime control programs were reviewed and forward searches for works that cited seminal hot spots policing studies were performed. Bibliographies of past completed Campbell systematic reviews of police crime prevention efforts were reviewed and hand searches of leading journals in the field were completed. Experts in the field were consulted and relevant citations were obtained. Selection Criteria: To be eligible for this review, interventions used to control crime hot spots were limited to police-led prevention efforts. Suitable police-led crime prevention efforts included traditional tactics such as directed patrol and heightened levels of traffic enforcement as well as alternative strategies such as aggressive disorder enforcement and problem-oriented policing. Studies that used randomized controlled experimental or quasiexperimental designs were selected. The units of analysis were limited to crime hot spots or high-activity crime "places" rather than larger areas such as neighborhoods. The control group in each study received routine levels of traditional police crime prevention tactics. Data Collection and Analysis: Sixty-five studies containing 78 tests of hot spots policing interventions were identified and full narratives of these studies were reported. Twenty-seven of the selected studies used randomized experimental designs and 38 used quasiexperimental designs. A formal meta-analysis was conducted to determine the crime prevention effects in the eligible studies. Random effects models were used to calculate mean effect sizes. Results: Sixty-two of 78 tests of hot spots policing interventions reported noteworthy crime and disorder reductions. The meta-analysis of key reported outcome measures revealed a small statistically significant mean effect size favoring the effects of hot spots policing in reducing crime outcomes at treatment places relative to control places. The effect was smaller for randomized designs but still statistically significant and positive. When displacement and diffusion effects were measured, a diffusion of crime prevention benefits was associated with hot spots policing. Authors' Conclusions: The extant evaluation research suggests that hot spots policing is an effective crime prevention strategy. The research also suggests that focusing police efforts on high-activity crime places does not inevitably lead to crime displacement; rather, crime control benefits may diffuse into the areas immediately surrounding the targeted locations.