The Probabilistic Genotyping Software STRmix: Utility and Evidence for its Validity

Forensic DNA interpretation is transitioning from manual interpretation based usually on binary decision‐making toward computer‐based systems that model the probability of the profile given different explanations for it, termed probabilistic genotyping (PG). Decision‐making by laboratories to implement probability‐based interpretation should be based on scientific principles for validity and information that supports its utility, such as criteria to support admissibility. The principles behind STRmix? are outlined in this study and include standard mathematics and modeling of peak heights and variability in those heights. All PG methods generate a likelihood ratio (LR) and require the formulation of propositions. Principles underpinning formulations of propositions include the identification of reasonably assumed contributors. Substantial data have been produced that support precision, error rate, and reliability of PG, and in particular, STRmix?. A current issue is access to the code and quality processes used while coding. There are substantial data that describe the performance, strengths, and limitations of STRmix?, one of the available PG software.     

Did Post-Floyd et al. Reforms Reduce Racial Disparities in NYPD Stop,Question, and Frisk Practices? An Exploratory Analysis Using External and Internal Benchmarks

Various methodological approaches to constructing external and internal benchmarks have been applied to estimate racial bias in police stop, question, and frisk (SQF) patterns. We apply an external benchmark of the race of the residential population and an internal benchmark of similarly-situated stops to estimate if racial disparities in New York City SQF data were impacted by the Floyd, et al. v. City of New York court settlement. We find that after the settlement, the racial composition of census tracts were no longer significant predictors of the stop rate after controlling for reported crime, socioeconomic factors, and police precincts. We further find that differences in SQF outcomes and hit rates between Blacks and Hispanics and similarly-situated others diminished substantially after the settlement. These findings suggest that court reforms may be an effective method for reducing racial disparities in SQF patterns.     

In a World of Their Own: Security‐cleared Counsel,Best Practice,and Procedural Tradition

This article charts how security‐cleared counsel have been constructed as a mechanism for managing the tension between security and fairness in secret trials and transferred across national boundaries as an example of ‘best practice', before going on to evaluate recent cross‐cultural and transnational research on this ‘best practice'. Particular attention is paid to the central role played by the European Court of Human Rights (ECtHR) in promoting the role of ‘special advocates’ and a contrast is made between the methodologies deployed by the Court and those used in recent research to identify and problematize ‘best practice’ within the closed world of security‐cleared counsel. The article then goes on to explore the relationship between ‘best practice’ and procedural tradition and argues that normative solutions advancing ‘best practice’ need to pay careful attention to the procedural contexts and cultures in which they are embedded.     

Evaluating the Role of Race in Sentencing: An Entropy Weighting Analysis

The current study builds on prior research examining racial disparities in sentencing. Entropy weighting is introduced as a new method for estimating racial disparities that has several advantages over traditionally used methods. Entropy weighting is compared to regression and propensity score methods in estimating Black-White disparities in incarceration sentences. Although all methods find non-significant racial disparities in incarceration sentences, regression and propensity score methods underestimate disparities in incarceration sentence lengths. Entropy weighting provides comparable estimates to propensity score methods, but assures that the samples are identical on all covariates aside from race. The method offers researchers a useful and flexible approach for estimating racial disparities in criminal justice, and its use may lead to alternative conclusions about the size and presence of racial disparities in sentencing.     

Characterization and differentiation of cyclopropylfentanyl from E-crotonylfentanyl, Z-crotonylfentanyl,and 3-butenylfentanyl

Recently, a sample containing cyclopropylfentanyl was analyzed at this laboratory. Cyclopropylfentanyl began to appear in the United States' illicit drug markets in 2017. Unfortunately, cyclopropylfentanyl presents an analytical challenge due to its mass spectrum being almost identical to that of crotonylfentanyl. There are two possible isomers of crotonylfentanyl, Z- and E- crotonylfentanyl. In order to provide sufficient analytical data to distinguish the two isomers of crotonylfentanyl and cyclopropylfentanyl, crotonylfentanyl was synthesized and fully characterized. Each isomer was analyzed via nuclear magnetic resonance spectroscopy, gas chromatography–mass spectrometry, and Fourier transform infrared spectroscopy. During the synthesis of crotonylfentanyl, an unknown compound was formed. The identification of this compound and the analytical characterization of the two isomers of crotonylfentanyl are presented. Through the comparison of these compounds, it was confirmed that cyclopropylfentanyl can be differentiated from crotonylfentanyl.     

Toward Better Outcomes for Families Through Innovative Dispute Resolution Programs in England

This article explores and shares the learning from two of Cafcass’ innovative dispute resolution pilot programs. The programs aim to improve outcomes for families against the backdrop of rising private law demand in England, while keeping the child at the center. The Positive co‐Parenting Programme pilot provides a structured intervention to reduce conflict and promote timely resolution for children and families in complex cases. The Support with Making Child Arrangements pilot explores whether the provision of a package of support to parents ahead of the first court hearing can help them come to safe agreements about their children without the need for court intervention.