Bounding the number of contributors to mixed DNA stains

We derive a simple inequality for the probability of observing a given DNA profile when assuming a fixed number of unknown persons have contributed to the mixed stain. We then show how this inequality can be used to obtain an upper bound for the number of unknown contributors needed to be considered.     

Are DNA data a valid source to study the spatial behavior of unknown offenders?

Studying the spatial behaviour of unknown offenders (i.e. undetected offenders) is difficult, because police recorded crime data do not contain information about these offenders. Recently, forensic DNA data has been used to study unknown offenders. However, DNA data are only a subset of the crimes committed by unknown offenders stored in police recorded crime data. To establish the suitability of DNA data for studying the spatial offending behaviour of unknown offenders, we examine the concentration and spatial similarity of detected but unsolved crimes in police recorded crime data (N?=?181,483) and DNA data (N?=?1913) over 27 Belgian judicial districts for four crime types. We established spatial similarity for certain crime types (in some districts). This offers opportunities for DNA data to be used to study unknown offenders' spatial offending behaviour. Implications for theory and research are discussed.     

Validating TrueAllele® Interpretation of DNA Mixtures Containing up to Ten Unknown Contributors

Most DNA evidence is a mixture of two or more people. Cybergenetics TrueAllele^® system uses Bayesian computing to separate genotypes from mixture data and compare genotypes to calculate likelihood ratio (LR) match statistics. This validation study examined the reliability of TrueAllele computing on laboratory-generated DNA mixtures containing up to ten unknown contributors. Using log(LR) match information, the study measured sensitivity, specificity, and reproducibility. These reliability metrics were assessed under different conditions, including varying the number of assumed contributors, statistical sampling duration, and setting known genotypes. The main determiner of match information and variability was how much DNA a person contributed to a mixture. Observed contributor number based on data peaks gave better results than the number known from experimental design. The study found that TrueAllele is a reliable method for analyzing DNA mixtures containing up to ten unknown contributors.     

Calculating likelihood ratios for a mixed DNA profile when a contribution from a genetic relative of a suspect is proposed

This technical note describes a practical method for evaluating evidence in the case of a two person conditioned DNA mixture where the defence proposition is that the unknown contributor is genetically related to the suspect. A conditioned mixture is one where the presence of DNA from one of two individuals is accepted by both prosecution and defence. A typical example would be a vaginal swab in an alleged rape case, where the presence of the complainant's DNA would be expected and samples have been taken from the complainant and a suspect. Much has been written about the interpretation of such mixtures and the calculation of the conditional genotype probabilities that must be carried out. In general, such treatments assume that the unknown contributor, under the defence proposition, is unrelated to the known individuals. In this paper, we consider the case where the defence proposition is that the unknown contributor is genetically related to the suspect. We describe a method, incorporating a flow chart and reference tables that facilitate manual calculations of the likelihood ratio for several postulated genetic relationships.     

Forensic DNA Challenges: Replacing Numbers with Names of Fosse Ardeatine’s Victims*

Abstract: The Fosse Ardeatine massacre was a mass execution carried out in Rome on March 24, 1944 by Nazi German occupation troops during the Second World War as a reprisal for a partisan attack conducted on the previous day in central Rome. The 335 civilians were taken to the “Cave Ardeatine” and they were shot. Only 323 corpses out of 335 have been identified. The aim of this work is the genetic and anthropological analysis of the remains exhumed from grave number 329 of Fosse Ardeatine’s Shrine to assess their identity. So far, such remains have been supposed to belong to MM but mitochondrial analysis excluded a biological relationship to two living maternal relatives. Our analysis indicated that remains recovered in grave number 329 do not belong to MM. This result suggests that genetic analysis of the remains should be also applied to the other 12 unknown corpses to elucidate their identity.     

RACIAL INEQUALITY AND RACIALLY DISAGGREGATED HOMICIDE RATES: AN ASSESSMENT OF ALTERNATIVE THEORETICAL EXPLANATIONS*

This research considers the relationship between levels of racial inequality and homicide rates for a sample of 154 U.S. cities. We identfy four causal processes that have been cited in the theoretical literature to explain the link between racial inequality and criminal violence. These diflerent causal explanations imply distinctive relationships between racial inequality and different types of homicide rates disaggregated by the racial characteristics of victims and offenders. Accordingly, we examine the effects of racial inequality on racially disaggregated homicide rates, as well as on total rates. We also introduce factor scales to alleviate the common problem of multicollinearity. Our results reveal significant, positive coefficients for racial inequality in equations predicting total homicide rates and race-specific offending rates. These results offer greatest support for theoretical arguments emphasizing a generalized effect of racial inequality on the offending behavior of residents of metropolitan communities.     

Understanding Income Inequality in China: A Multi-Angle Perspective

Economic reforms have brought about spectacular growth and vast improvements of people’s living standards in China since 1978. In the meantime, unbalanced regional growth and income inequality have become two important concerns of future development. Most available studies on income distribution have either focused on the rural population or on the urban citizens. This paper stresses the importance of adopting a multi-angle approach to fully understand income inequality in China. We first use some top-down information to form a general picture of inequality for the whole country, and then use some bottom-up household survey data to explain in detail the development of inequality over time regarding rural/urban inequality, rural inequality, urban inequality and inter-regional inequality, the relative importance of different income sources to overall inequality.     

A novel method for STR-based DNA profiling using microarrays

We describe a novel method for rapidly identifying and distinguishing between different DNA sequences using short tandem repeat (STR) analysis and DNA microarrays. The method can be used to deduce identity, length, and number of STRs of the target molecule. We refer to this technique as the "variable-length probe array" method for STR profiling (VLPA). The method involves hybridization of the unknown STR target sequence to a DNA microarray displaying complementary probes that vary in length to cover the range of possible STRs. A post-hybridization enzymatic digestion of the DNA hybrids is then used to selectively remove labeled single-stranded regions of DNA from the microarray surface. The number of repeats in the unknown target is then deduced based on the pattern of target DNA that remains hybridized to the array. This DNA profiling technique is useful for performing forensic analysis to uniquely identify individual humans or other species.     

联合应用多个DNA位点进行尸源鉴定

目的　研究联合应用多个DNA位点在尸源鉴定方面的应用价值。方法　应用聚合酶链反应(PCR)、聚丙烯酰胺凝胶电泳分离及银染显带的方法通过对无名尸体的有关检材与可疑双亲或子女进行亲权鉴定。结果　在 80例刑事案件尸源鉴定中 ,38例无名尸体采用较新鲜肌肉 ,通过扩增VNTR、STR多个位点得以判明尸源 ;2 9例采用腐败肌肉、 6例采用骨骼和 2例采用牙齿 ,通过扩增多个STR位点判明了尸源。仅有 1例采用腐败肌肉、 2例采用骨骼未能确定尸源。结论　运用多个位点进行亲权方法可以准确地判明尸源鉴定 ,特别对高度腐败尸体、尸块不全等情况下的尸源鉴定具有很高的实用价值     

A State Census of Unsubmitted Sexual Assault Kits: Comparing Forensic DNA Testing Outcomes by Geographic and Population Density Characteristics*

A growing number of U.S. cities and states have large numbers of unsubmitted sexual assault kits (SAKs) in police property facilities. Prior research conducted in large urban cities has found that testing these kits yields a sizable number of DNA profiles that meet FBI eligibility for upload to the national criminal DNA database CODIS (Combined DNA Index System) and uploaded profiles return a substantial number of matches to existing criminal profiles in CODIS. It is unknown whether these findings are unique to large urban cities with high crime rates. The purpose of current study was to document forensic testing outcomes from a state census of previously unsubmitted SAKs, which included large urban–suburban centers, as well as smaller cities and rural counties. We inventoried all previously unsubmitted SAKs in Michigan (N = 3422 SAKs) and submitted all kits for forensic DNA testing. A total of n = 1239 SAKs had a DNA profile that met eligibility for upload into CODIS (36.2% unconditional, 56.5% conditional CODIS eligible rate) and n = 585 SAKs yielded a CODIS Hit (17.1% unconditional, 47.2% conditional CODIS hit rate). These rates are consistent with studies from urban areas suggesting approximately half of SAKs tested yield a CODIS profile and approximately half of those uploaded profiles yield a hit. We compared SAK forensic testing outcomes by geographic and population density characteristics, and although rates were often higher in larger metropolitan areas, the obtained rates in micropolitan and rural areas suggest testing is warranted in smaller jurisdictions as well.     

The Environmental Justice Movement: Equitable Allocation of the Costs and Benefits of Environmental Management Outcomes

We present a review of theoretical and methodological advances in the social scientific literature on environmental inequality/racism and argue for new directions in research efforts that pay more attention to (1) the historical forces driving environmental justice conflicts; (2) the complex role of stakeholders in these struggles; (3) the role of social inequality, particularly the trade-offs between environmental protection and social equity; and (4) the impact of social movement activity on the state of environmental protection. Drawing on a case study of an environmental justice conflict in the United States, we find that environmental inequality impacts many actors with often contradictory and cross-cutting allegiances. These struggles therefore become a moving drama—a process—rather than a cross-sectional outcome. We conclude with an analysis of environmental inequality on a global scale and argue that the role of transnational capital remains largely untheorized in the literature. We suggest new models for explaining environmental inequality's causes and consequences.     

Identification and separation of DNA mixtures using peak area information

We introduce a new methodology, based upon probabilistic expert systems, for analysing forensic identification problems involving DNA mixture traces using quantitative peak area information. Peak area is modelled with conditional Gaussian distributions. The expert system can be used for ascertaining whether individuals, whose profiles have been measured, have contributed to the mixture. It can also be used to predict DNA profiles of unknown contributors by separating the mixture into its individual components. The potential of our probabilistic methodology is illustrated on case data examples and compared with alternative approaches. The advantages are that identification and separation issues can be handled in a unified way within a single probabilistic model and the uncertainty associated with the analysis is quantified. Further work, required to bring the methodology to a point where it could be applied to the routine analysis of casework, is discussed.     

Simulated approach to estimate the number and combination of known/unknown contributors in mixed DNA samples using 15 short tandem repeat loci

The calculation of likelihood ratios (LRs) for DNA mixture analysis is necessary to establish an appropriate hypothesis based on the estimated number of contributors and known contributor genotypes. In this paper, we recommend a relevant analytical method from the 15 short tandem repeat typing system (the Identifiler multiplex), which is used as a standard in Japanese forensic practice and incorporates a flowchart that facilitates hypothesis formulation. We postulate that: (1) all detected alleles need to be above the analytical threshold (e.g., 150 relative fluorescence unit (RFU)); (2) alleles of all known contributors should be detected in the mixture profile; (3) there should be no contribution from close relatives. Furthermore, we deduce that mixtures of four or more persons should not be interpreted by Identifiler as the LR values of 100,000 simulated cases have a lower expectation of exceeding our temporal LR threshold (10,000) which strongly supports the prosecution hypothesis. We validated the method using various computer-based simulations. The estimated number of contributors is most likely equal to the actual number if all alleles detected in the mixture can be assigned to those from the known contributors. By contrast, if an unknown contributor(s) needs to be designated, LRs should be calculated from both two-person and three-person contributions. We also consider some cases in which the unknown contributor(s) is genetically related to the known contributor(s).     

Perceptions of Economic Inequality and Support for Redistribution: The role of Existential and Utopian Standards

Perceived greater economic inequality is supposedly associated with higher demand for redistribution. However, the findings in the literature are mixed in this regard, with some researchers providing evidence in favour of this association and some findings evidence against it. Given that perceived economic inequality and endorsement of system-justifying beliefs are related to increased inequality acceptance, we explore the interplay between them in relation to support for redistribution. This study is intended to shed light on the role of utopian standards (ideal estimates about what ought to be) as one mechanism that affects the relationship between perceived greater economic inequality and support for redistribution. Based on correlational data (N?=?794), we conducted a conditional process analysis and found that perceived greater inequality displayed a negative indirect effect on support for redistribution, through acceptance of ideal level of economic inequality: Perception of higher inequality was related to increased ideal levels of inequality and thus with lower support for redistribution. In addition, we found that economic system-justifying beliefs conditioned the effect of perceived economic inequality in two ways: First, perceived economic inequality was positively associated with higher acceptance of inequality, and this association was stronger for those that justified the economic system more, and perceived greater inequality was associated with higher support for redistribution—but only for those who endorsed lower levels of economic system justification beliefs. These findings provide evidence that perceived greater economic inequality does not in itself lead to a push for more redistribution; rather, utopian standards such as ideal estimates of economic inequality, which are conditioned by system-justifying ideologies.     

MiniFiler试剂盒运用于法医微量物证的检验

目的应用MiniFiler试剂盒对法医微量物证进行DNA分析。方法采用MiniFiler试剂盒对样本进行DNA分型,确定样本9个STR基因座的等位基因型。结果10pg DNA模板经MiniFiler试剂盒扩增后,能够进行DNA分型,但40pg以上的DNA方可得到稳定可靠的分型结果。结论MiniFiler试剂盒可以用于法医微量物证的STR分析。     

The effective design,implementation and enforcement of socio-economic equality duties: lessons from the pupil premium

Abstract

The UK has extremely high levels of socio-economic inequality, which are predicted to rise over the next five years. Traditionally, equality law was seen as inappropriate to address socio-economic inequality but in the last decade, a growing number of equality duties have been introduced to address this persistent form of inequality. There is, however, little research on the principles that underpin these duties. This article seeks to address this gap through the use of data from interviews conducted with primary school personnel implementing the pupil premium. The article explores understandings of socio-economic inequality by individuals in schools; policy conflicts; the wider context of action to address socio-economic inequality; different decision-making processes; and accountability mechanisms. On the basis of the findings of this study, broad principles are outlined to inform the design, implementation and enforcement of socio-economic equality duties in the future.     

Crack as Proxy: Aggressive Federal Drug Prosecutions and the Production of Black–White Racial Inequality

In this article, we empirically examine jurisdictional variations in federal crack prosecutions to measure whether aggressive crack prosecutorial practices are associated with racial inequality in federal caseload characteristics and outcomes. Building on theories that address the production of inequality in institutional settings, we hypothesize that U.S. Attorneys’ offices that are more proactive in charging defendants with crack, relative to other kinds of drugs, and relative to case strength and seriousness, will demonstrate higher rates of black–white racial inequality in case outcomes across the entire criminal caseload. Consistent with theories of institutional racism, our findings demonstrate that aggressive crack prosecutions at the district level are a strong predictor of black–white inequality in conviction rates across the entire criminal caseload, and a much more modest predictor of inequality in final sentence outcomes. We conclude by discussing the importance of organizational‐level empirical analyses for more effectively uncovering the conditions under which inequality can and does flourish in legal settings, and suggest possible future lines of inquiry along these lines.     

Reassessing the Cross-National Relationship Between Income Inequality and Homicide Rates: Implications of Data Quality Control in the Measurement of Income Distribution

A significant positive relationship between income inequality and homicide rates has been found in a large number of cross-sectional studies and a few longitudinal analyses; a theoretically interesting interaction effect between income inequality and social welfare has also been found. For the most part researchers have been willing to use generous quality criteria in collecting income-distribution data, to maximize sample size and thereby enhance statistical power and representativeness. In the present paper we use a recently developed data set with explicit quality ratings for the income-distribution data, which permits systematic assessment of the consequences of relying on income-distribution measures of varying quality in examining the inequality-homicide relationship. Our analyses reveal that the income inequality-homicide relationship is remarkably robust in cross-sectional analyses. Regardless of the quality of income-distribution data, we observe significant positive effects of the Gini coefficient on homicide rates in cross-sectional multivariate models. Consistent results are also observed when an interaction term for income inequality and decommodification is examined. The results of longitudinal analyses differ; we observe a significant positive effect of changes in inequality on changes in homicide rates only when income-distribution measures of low quality are used.     

Introducing eNoC – A simple,excel-based tool for improved assignment of the number of contributors (NoC) to a mixture

Assigning NoC in a mixed STR profile is an important preliminary step in computing a likelihood ratio (LR). A common metric is maximum allele count (MAC) whereby the locus exhibiting the largest number of alleles is used to set the NOC. This metric can be supplemented by considering total allele count (TAC) and locus allele count (LAC). TAC is the total number of alleles across all loci and is compared with probability distributions generated in silico. LAC works similarly, save that the probability distributions are generated at the locus level. Herein, we present a comparative analysis of these three metrics using a dataset of 10,000 of each of 2–7 person simulated ground truth mixtures. These datasets were used to generate parameter distributions for each NoC. This analysis showed LAC to be the most accurate single metric in all circumstances tested. We have developmentally validated an excel-based tool to automate calculations for use by operational caseworkers.     

A multifaceted,multijurisdictional, multiagency,and multidisciplinary approach to investigating unidentified and missing persons cases in Australia

Currently, there are approximately 750 unidentified human remains and 2500 long-term missing persons in Australia. The Australian Federal Police National DNA Program for Unidentified and Missing Persons (Program) is using a multifaceted, multijurisdictional, multiagency, and multidisciplinary approach in a dedicated effort to identify these unknown deceased persons, scientifically link them to known missing persons, and provide answers to their families. The nationally coordinated Program provides its police, forensic, and coronial stakeholders with a suite of contemporary forensic technologies, databases, and experts to forensically examine the skeletonised remains and recover post-mortem data for comparison to the available ante-mortem data for each missing person. Through a number of physical and virtual public outreach activities, families with missing relatives have been encouraged to provide vital ante-mortem forensic information, records, and samples to aid the identification process. To date, this unique Program has assisted to resolve a number of unidentified and missing persons cases from both historical and contemporary contexts, using a combination of genetic and non-genetic techniques, and local and national databases. The centralisation of Program capabilities, expertise, and resources to conduct this type of unique and challenging casework is proving to be the most effective and efficient way to generate investigative leads, identify human remains, and resolve long-term missing persons cases in Australia.