A mixed DNA profile controversy revisited

Semaan et al. (J Forensic Res, 2020, 11, 453) discuss a mock case “where eight different individuals [P₁ through P₈] could not be excluded in a mixed DNA analysis. Even though … expert DNA mixture analysis software was used.” Two of these are the true donors. The LRs reported are incorrect due to the incorrect entry of propositions into LRmix Studio. This forced the software to account for most of the alleles as drop-in, resulting in LRs 60–70 orders of magnitude larger than expected. P₁, P₂, P₄, P₅, and P₈ can be manually excluded using peak heights. This has relevance when using LRmix which does not use peak heights. We extend the work using the same two reference genotypes who were the true contributors as Semaan et al. (J Forensic Res, 2020, 11, 453). We simulate three two-donor mixtures with peak heights using these two genotypes and analyze using STRmix?. For the simulated 1:1 mixture, one of the non-donors’ LRs supported him being a contributor when no conditioning was used. When considered in combination with any other potential donors (i.e., with conditioning), this non-donor was correctly eliminated. For the 3:1 mixture, all results correctly supported that the non-donors were not contributors. The low-template 4:1 mixture LRs with no conditioning showed support for all eight profiles as donors. However, the results from pair-wise conditioning showed that only the two ground truth donors had LRs supporting that they were contributors to the mixture. We recommend the use of peak heights and conditioning profiles, as this allows better sensitivity and specificity even when the persons share many alleles.     

Metric forensic anthropology decisions: Reliability and biasability of sectioning-point-based sex estimates

Subjective decisions make human cognitive processes more susceptible to bias and error. Specifically, research indicates that additional context biases forensic anthropologists’ morphological analyses. To address whether metric analyses are also subject to bias, we conducted a pilot study in which 52 experienced osteologists measured a difficult-to-classify human femur, with or without additional contextual information. Using a metric sectioning-point sex-estimation method, participants provided a sex estimate for individual skeletal element(s) and, when given multiple elements, the combined skeletal assemblage. Control group participants (n = 24) measured only the femur. In addition to the femur, bias group participants (n = 28) either measured a female humerus and viewed a female-biasing photograph (n = 14) or measured a male humerus and viewed a male-biasing photograph (n = 14). We explored whether the experts in the different groups would differ in: (1) femoral measurements; (2) femoral sex-estimation conclusions; and (3) final sex-estimation conclusions for the skeletal assemblage. Although the femoral measurements and femoral sex estimates were comparable across groups, the overall sex estimates in the female-biased group were impacted by contextual information—differing from both the control and male-biased groups (p < 0.001). Our results demonstrate that cognitive bias can occur even in metric sex-estimation conclusions. Specifically, this occurred when the metric data and single-element sex estimates were synthesized into an overall estimate. Thus, our results suggest that metric methods are most vulnerable to bias when data are synthesized into an overall conclusion, highlighting the need for bias countermeasures and comprehensive statistical frameworks for synthesizing metric data to mitigate the effects of cognitive bias.     

Applying Moral Foundations Theory to the Explanation of Capital Jurors’ Sentencing Decisions

Abstract

This study applies moral foundations theory to capital juror decision making. We hypothesized that binding moral foundations would predict death qualification and punitive sentencing decisions, whereas individualizing moral foundations would be associated with juror disqualification and a leniency effect. Additionally, we considered whether moral foundations can explain differences in death penalty application between conservatives and liberals. Respondents from two independent samples participated in a mock-juror task in which the circumstances of a hypothetical defendant’s case varied. Results revealed moral foundations were strong predictors of death qualification. The binding and individualizing foundations were related to sentencing decisions in the expected ways. Supporting our contention that moral foundations operate differently across different types of cases, heterogeneity in the effects of moral foundations was observed. Finally, we found support for the hypothesis that the relationship between sentencing decisions and conservatism would be attenuated by moral foundations.     

What do forensic analysts consider relevant to their decision making?

In response to research demonstrating that irrelevant contextual information can bias forensic science analyses, authorities have increasingly urged laboratories to limit analysts' access to irrelevant and potentially biasing information (Dror and Cole (2010) [3]; National Academy of Sciences (2009) [18]; President's Council of Advisors on Science and Technology (2016) [22]; UK Forensic Science Regulator (2015) [26]). However, a great challenge in implementing this reform is determining which information is task-relevant and which is task-irrelevant. In the current study, we surveyed 183 forensic analysts to examine what they consider relevant versus irrelevant in their forensic analyses. Results revealed that analysts generally do not regard information regarding the suspect or victim as essential to their analytic tasks. However, there was significant variability among analysts within and between disciplines. Findings suggest that forensic science disciplines need to agree on what they regard as task-relevant before context management procedures can be properly implemented. The lack of consensus about what is relevant information not only leaves room for biasing information, but also reveals foundational gaps in what analysts consider crucial in forensic decision making.     

应用硅珠法提取陈旧骨骼DNA

骨骼相对于人体其他的组织脏器腐败降解慢,是进行高度腐败及白骨化样本DNA检验的唯一检材。但骨骼DNA的提取比较困难,本文运用传统的硅珠法提取骨骼DNA取得了很好的效果。1材料与方法1.1样本1~4年水浸泡、土埋的股骨、肱骨等样本,来自本实验室日常检案检材。1.2方法1.2.1骨骼DNA提取用水洗净骨骼表面,晾干。锯成小块,用锉打磨内外表面。去离子水、乙醇和5%bleach浸泡、晾干,磨成粉末。取骨粉5g;加入0.5mon/L EDTA(pH8.0)溶液,搅拌均匀置于摇床上脱钙12h,去离子水洗两遍,去上清,重复4次[1];沉渣中加入适量裂解液(6mon/L GuSCN,20mo…     

高校贫困生人际交往障碍的个案研究

受经济贫困的影响,许多高校贫困生出现了比较严重的人际交往障碍,这主要是由于缺乏良好的心理品质和能力,产生认知障碍、心理障碍和能力障碍造成的.在解决高校贫困生人际交往障碍的过程中还存在诸多问题与不足.我们应构建主体多元化的社会支持网络.设置专门机构,采取社会工作专业方法,开展有针对性的活动.     

论增强党的阶级基础、扩大党的群众基础的必要性

在新世纪 ,增强党的阶级基础、扩大党的群众基础是建设有中国特色社会主义事业的必然要求 ;是改革开放以来我国社会阶级、阶层发生深刻变化带来的新要求 ;是新世纪加强党的建设的根本要求。     

网上查找法律案例的方法与技巧

网上检索法律案例均需要一些分析课题、选择检索工具、选择检索途径的方法和技巧,并一些适用的网站可供选择。     

A NEW LOOK AT AN OLD ISSUE:

In 1997, the Office of Child Support Enforcement initiated the State Child Access and Visitation (AV) Grant Program, which involves annual awards of $10 million to states to promote the development of programs to alleviate access problems. Telephone interviews with 970 parents who used mediation, parent education, and supervised visitation programs funded by AV grants in nine states revealed that the programs are reaching diverse groups of parents including many low-income, non-White, and unmarried parents who receive no other type of access assistance. The programs also appear to be achieving the major objectives posited for them by the federal government. One-third to one-half of noncustodial parents in every program type reported that parent–child contact increased following program participation, with supervised visitation users who typically had the lowest levels of parent–child contact reporting a significant increase in the number of days of contact. A review of child support records for 173 program users in three states revealed that child support payments increased among participants following program participation, especially for never-married parents who paid a significantly higher proportion of what they owed. These findings are similar to results reported in a five-state study of mediation programs funded by AV grants that was conducted by the Office of the Inspector General. However, both studies have some serious limitations, including low response rates and the absence of a nontreatment comparison group.     

DNA commission of the International Society of Forensic Genetics: Recommendations on the interpretation of mixtures

The DNA commission of the International Society of Forensic Genetics (ISFG) was convened at the 21st congress of the International Society for Forensic Genetics held between 13 and 17 September in the Azores, Portugal. The purpose of the group was to agree on guidelines to encourage best practice that can be universally applied to assist with mixture interpretation. In addition the commission was tasked to provide guidance on low copy number (LCN) reporting. Our discussions have highlighted a significant need for continuing education and research into this area. We have attempted to present a consensus from experts but to be practical we do not claim to have conveyed a clear vision in every respect in this difficult subject. For this reason, we propose to allow a period of time for feedback and reflection by the scientific community. Then the DNA commission will meet again to consider further recommendations.