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Research summary: The concern of crime in New York City public housing complexes motivated heightened police patrol of buildings and the enforcement of trespass laws. The 2013 federal court settlement of Davis et al. v. City of New York et al. mandated that the New York City Police Department (NYPD) implement a series of reforms, including the deployment of body‐worn cameras (BWCs) on officers, to address unconstitutional use of criminal trespass enforcement and stop and frisk practices in public housing developments. This study employed a stepped wedge quasi‐experimental design that involved the sequential crossover of public housing service area clusters from control to BWC implementation until all NYPD housing bureau officers were equipped with BWCs. Panel regression models at the individual officer and service area levels were used to estimate BWC program impacts on outcomes between 2015 and 2019. Logistic regression models were used to estimate the impact of the BWCs on the lawfulness of officer stop reports that were randomly selected for audit between 2017 and 2019. Results show that BWC deployment in public housing reduced excessive enforcement, citizen complaints, and use of force by NYPD housing officers. Findings further suggest that BWCs can help reduce constitutionally problematic stops and frisks of citizens. Policy implications: Problematic police activities in public housing contexts can be reformed using BWCs. When coupled with routine supervisory review of video footage, the deployment of BWCs on public housing officers can improve compliance with department directives to reduce enforcement actions and increase documentation of citizen stops. [ABSTRACT FROM AUTHOR]

Research Summary Policy Implications The evaluation literature suggests that focused deterrence strategies are effective in reducing gun violence. However, focused deterrence is notoriously difficult to implement and sustain. The history of focused deterrence implementation failure raises questions about its viability as a gun violence prevention strategy. Stockton, California, implemented focused deterrence three times during the past 25 years. In its most recent version, Stockton officials explicitly designed the strategy to be a permanent feature of the city's violence prevention portfolio. Although program caseloads diminished over the course of the COVID‐19 pandemic and the strategy faced leadership and resource challenges, Stockton's efforts prevented the program from being discontinued and, for those gang members who did receive treatment, delivered a robust gun violence prevention strategy. A quasi‐experimental evaluation shows that treated gang members were less likely to be shot and reduced their violent offending relative to similar untreated gang members. The focused deterrence impacts also appear to spill over to gang members who were socially connected to treated gang members. Although Stockton experienced an increase in homicides over the course of the COVID‐19 pandemic, the increase was not as steep as other comparable California cities.Focused deterrence strategies can be effective responses to gun violence problems when implemented properly. A priori planning is essential when jurisdictions prepare to adopt focused deterrence. Strategic management actions, such as maintaining a robust network of partnering agencies, developing accountability structures and sustainability plans, and conducting upfront and ongoing problem analysis, are critical elements that must be in place for focused deterrence to be effective and sustainable. [ABSTRACT FROM AUTHOR]

CO2 mineralization in slag has been widely investigated as a potential solution for offsetting steelmaking industry emissions. However, it can be associated with ecotoxic elements release (e.g., V and Cr). The presence of such elements in heterogenous slag at the micro‐scale remains difficult for analysis since microstructural features can be missed during microscopy data inspection, thereby presenting a challenge in understanding how ecotoxic elements exist in slag. Here, an unsupervised machine learning‐based technique is used to analyze slag's microstructural features. Energy Dispersive Spectroscopy (EDS) data are analyzed through Hierarchical Density‐Based Spatial Clustering of Applications with Noise (HDBSCAN) method. Results show that passive CO2 mineralization has occurred in situ in the studied samples, on the surface, and within their pores. Additionally, V and Cr regions with equivalent diameters < 42 µm can exist within slag, potentially making such elements prone to mobilization due to slag pulverization. Interrogation of the samples with Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA‐ICP‐MS) confirms the distribution of the elements obtained from the clustering algorithm and further demonstrates that up to 84 and 9 ppm of V and Cr are incorporated in the precipitated calcite, respectively. This implies that ecotoxic elements may be immobilized through calcite precipitation. [ABSTRACT FROM AUTHOR]