Whole-genome sequencing of degraded DNA for investigative genetic genealogy

Whole genome sequencing has opened the doors to Investigative genetic genealogy (IGG) analysis of challenging forensic samples that are not suitable for microarray genotyping. These samples still do not typically achieve high enough coverage for direct genotype calling, therefore a pipeline for imputation from low coverage sequencing data was evaluated using data from the 1000 Genomes Project. This pipeline generated results suitable for IGG down to 0.25X coverage. Additionally, forensic samples from a variety of tissue types and input amounts were sequenced and successfully uploaded to genetic genealogy databases after imputation.     

A method to enable forensic genetic genealogy investigations from DNA mixtures

The presence of more than one DNA contributor in an evidentiary sample may preclude attempts to use forensic genetic genealogy to develop an investigative lead. To address this issue, we developed a workflow for deconvolution of SNP mixtures into single source profiles that are suitable for matching against a genealogical database. Using the method, two-contributor DNA mixtures assayed using a commercial SNP typing kit can produce informative match results for both major and minor contributors.     

Y-chromosomal kinship estimation for forensic familial searching: YMrCA to the rescue

The Y-chromosome can be used as an identification method to find paternally related males of the perpetrator. When a close Y-haplotype match is identified, the time to their most recent common ancestor (tMRCA) needs to be estimated to reconstruct their genealogy. To date, two mutation models and three online tMRCA calculators exist. But, they do not include individual mutation rates with multi-step changes, while ignoring hidden multiple, back or parallel modifications. To improve tMRCA estimation, we developed a user-friendly calculator, the ‘YMrCA’, including all previously mentioned mutation characteristics. Here, a case using genealogical pairs with confirmed biological kinships visualizes the good estimation performance of the YMrCA compared to the state-of-the-art. Even when genealogical pairs have equal number of mutations, the YMrCA still estimates the correct number of generations due to the inclusion of individual Y-STR mutation rates and the different mutational influencing factors.     

Unlocking the potential of forensic traces: Analytical approaches to generate investigative leads

Forensic investigation involves gathering the information necessary to understand the criminal events as well as linking objects or individuals to an item, location or other individual(s) for investigative purposes. For years techniques such as presumptive chemical tests, DNA profiling or fingermark analysis have been of great value to this process. However, these techniques have their limitations, whether it is a lack of confidence in the results obtained due to cross-reactivity, subjectivity and low sensitivity; or because they are dependent on holding reference samples in a pre-existing database. There is currently a need to devise new ways to gather as much information as possible from a single trace, particularly from biological traces commonly encountered in forensic casework. This review outlines the most recent advancements in the forensic analysis of biological fluids, fingermarks and hair. Special emphasis is placed on analytical methods that can expand the information obtained from the trace beyond what is achieved in the usual practices. Special attention is paid to those methods that accurately determine the nature of the sample, as well as how long it has been at the crime scene, along with individualising information regarding the donor source of the trace.     

Securing reliable information in investigative interviews: coercive and noncoercive strategies preceding turning points

ABSTRACT

Investigative interviewers apply a range of physical, cognitive, social or legalistic strategies to secure information from suspects. The perceived effectiveness of coercive and noncoercive strategies on turning points was examined by interviewing 34 practitioners and 30 high value detainees in East Asian and Western jurisdictions. Each recounted an interview with an initially uncooperative detainee who became cooperative, or an initially cooperative detainee who became resistant or silent. Analyses of interview narratives identified perceived turning points in the practitioner-suspect relationship associated with clear outcomes. Independent of jurisdiction, 56% of the noncoercive strategies were associated with cooperation, yielding reliable information in 49.4% and true admissions in 20.0% of the cases. In contrast, coercive strategies were perceived as more ineffective (58.9%) than effective (14.6%) in securing information. Physical coercion, intimidation and deception were most frequently acknowledged to yield false information. These findings suggested prioritisation of noncoercive social and physical interview strategies and international consensus on best practices.     

Development and evaluation of multiplex Y-STR assays for application in molecular genealogy

Three multiplex PCRs were developed for the analysis of 14 single-copy and 4 multi-copy Y chromosome Short Tandem Repeat (STR) loci routinely used by several public genealogical databases. These assays were used in addition to PowerPlex^® Y for the analysis of 245 DNA samples from a genealogical project. In total 244 different haplotypes composed of 37–40 alleles were identified with one haplotype identical between two males with the same surname. The multi-copy loci DYS464 and DYS724 were the most polymorphic with a gene diversity of at least 0.964. The use of DYS454 and DYS455 can be questioned as these loci had the lowest gene diversity (0.039 and 0.269, respectively).     

The ForAPP: Forensic Ancestry Prediction Pipeline for the interpretation of ancestry informative markers

Interpretation of ancestry informative markers (AIMs) in a forensic case can be time-consuming as different tools are used that need to be initiated separately. We develop the ForAPP; an open-source pipeline (running offline) that initiates multiple ancestry prediction analyses and summarizes results in an interactive interface for interpretation of autosomal ancestry-informative markers.     

规则建立过程的知识考察——以“刘涌案”事件为空间

“刘涌案”曾经在中国法律界甚至更大的社会范围引起很大的轰动与反响。围绕着“刘涌案”审理与判决所出现的各种问题,法律界以及社会大众等群体间产生了不同的认识与主张,从而在社会空间中产生了一系列事件。本文首先通过对“刘涌案”事件中不同群体对该案的看法及所依知识的分析,概括描述了该事件呈现出的各种刑事诉讼法律知识的存在状态。然后,对这些知识在建立程序规则以解决事件冲突中体现出的特点与相互间的结构关系进行了分析,进而阐述了该案程序规则所依据的知识理论在事件发展中展现出逻辑与系谱。接着,由“刘涌案”事件引申,对更大范围的中国法治现代化中的诉讼法律知识型的品格、结构进行了分析。最后,反思了对现今知识型条件下的刑事诉讼理论构建及制度建设中出现的问题,特别提出了中国问题和中国经验的重要性。     

The use of the likelihood ratio for evaluative and investigative purposes in comparative forensic handwriting examination

This paper extends previous research and discussion on the use of multivariate continuous data, which are about to become more prevalent in forensic science. As an illustrative example, attention is drawn here on the area of comparative handwriting examinations. Multivariate continuous data can be obtained in this field by analysing the contour shape of loop characters through Fourier analysis. This methodology, based on existing research in this area, allows one describe in detail the morphology of character contours throughout a set of variables. This paper uses data collected from female and male writers to conduct a comparative analysis of likelihood ratio based evidence assessment procedures in both, evaluative and investigative proceedings. While the use of likelihood ratios in the former situation is now rather well established (typically, in order to discriminate between propositions of authorship of a given individual versus another, unknown individual), focus on the investigative setting still remains rather beyond considerations in practice. This paper seeks to highlight that investigative settings, too, can represent an area of application for which the likelihood ratio can offer a logical support. As an example, the inference of gender of the writer of an incriminated handwritten text is forwarded, analysed and discussed in this paper. The more general viewpoint according to which likelihood ratio analyses can be helpful for investigative proceedings is supported here through various simulations. These offer a characterisation of the robustness of the proposed likelihood ratio methodology.     

Investigating the resolution of ancestry testing in geographic regions characterized by high population admixture

Ancestry testing can provide valuable information in forensic applications, but its efficiency has not yet been properly evaluated when used in highly admixed populations. In this work we tested a commercial ancestry panel containing 165 autosomal SNPs in 30 Dubai residents. Most of the tested individuals displayed, as expected, an admixed profile, but in general the main inferred ancestry was of Southwest Asian extraction, testifying that these tests can provide useful complementary forensic information.     

基于38-plex InDels的青海地区三个族群遗传推断

目的 基于38-plex InDels族群推断体系研究青海地区汉族、回族及撒拉族的族群成分与遗传结构.方法 使用38-plex InDels复合扩增体系检测3个族群的220份样本并获取InDels位点分型,利用主成分分析、STRUCTURE聚类分析及系统发育树综合分析族群之间的遗传关系,使用族群推断软件DAA v1.0...     

Public preferences and the challenge to genetic research policy

Modern genetic research requires scientists to collect, store, and study DNA samples and health information from thousands of people. Longstanding policy allows researchers to use samples and information without a person''s informed consent as long as the person''s identity is protected. Under existing policy, researchers must neither disclose study results to interested research participants nor compensate people who contribute to genetic research. Research and ethics experts developed these policy approaches without input from the people whose contributions are essential to the genetic research enterprise. A growing body of evidence shows that many research participants and would-be participants disagree with the current policy approaches. For ethical and practical reasons, participants should have a greater role in determining how genetic research is conducted.     

国家管辖范围外区域海洋遗传资源管理机制探究

国家管辖范围外区域蕴藏着丰富的海洋遗传资源,但现有的国际法尚未对其管理机制作出明确规定。近年来,国际社会在多个论坛对此问题展开讨论,并提出了一系列可供参考的解决进路。其中,扩大管理局的职能范围,使其能对海洋遗传资源进行有效管理具有诸多优势,但与发达国家的利益相左,实施难度较大;采用区域性管理机制能使特定区域纳入法律的运行轨道,却容易导致情势的碎片化;实施短效管理机制虽能防止形势恶化,可并不具有拘束力;制定一部《海洋法公约》的执行协定无疑是解决问题的最佳方式,也是未来的发展方向。     

侦查实验笔录简论

侦查实验是指侦查人员在刑事诉讼过程中按照科学的原则和方法,在模拟案件原有条件基础上所设计、实施的．旨在查明与案件有关的事实的存在、发生的可能性或其状态、过程的法科学活动。侦查实验笔录是侦查实验过程及结论的载体．是侦查人员按照法定格式制作的,用于描述和证明实验过程中发生的具有法律意义的事实状况的书面记录。在证据法学视野内...     

Police officers’ and Registered Intermediaries’ use of drawing during investigative interviews with vulnerable witnesses

ABSTRACT

Attempts to enhance episodic retrieval focus largely on verbal strategies which do not always address the limited or impaired free recall ability of vulnerable witnesses. Asking a witness to draw while recalling episodic information has long been deemed an effective method of improving communication and cognitive performance. Thus far, research has revealed these effects within laboratory settings but with scarce attention paid to real-life interview practice. In this paper, we explore police officers’ and Registered Intermediaries’ use of drawing during investigative interviews with vulnerable witnesses. A sample of specialist practitioners (n?=?85), comprising of vulnerable witness interviewing police officers (n?=?50) and Registered Intermediaries (n?=?35) completed a self-report questionnaire. As expected, frequent use of drawing was reported by both practitioner groups, and there was a positive correlation between reported use and perceived effectiveness. There were similarities between groups in reported techniques employed when using drawing, but some differences were apparent and these were attributed to the differing functions in police and Registered Intermediary roles. Overall, a consensus between empirical research and practice is evident, but these findings warrant further exploration in order to establish whether such practice is wide-spread.     

湖北地区德国牧羊犬10个微卫星DNA基因座遗传多态性研究

目的研究85头德国牧羊犬的10个基因座多态性。方法选用美国应用生物系统公司的10个商用犬微卫星基因座荧光标记复合扩增试剂盒进行PCR、并进行统计学分析。结果对85头德国牧羊犬的10个基因座的多态性研究表明,10个基因座累积DP值在0.9999972,非父排除率在0.9399,微卫星DNA基因座PEZ6、PEZ8、FHC2054的等位基因数均在8个以上,DP值接近或超过0.9,杂合度接近或超过0.7,能有效地应用犬的个体识别和亲权关系鉴定,其它7个基因座均未达到理想的个体识别和亲权鉴定使用条件。结论联合使用多个犬微卫星基因座,可以用于犬的个体识别和亲权鉴定。     

Update of aims population data and test with the genogeographer admixture module

Individuals from Slovenia, Greece, Albania, and Eritrea were typed with the Precision ID Ancestry Panel and included among GenoGeographer’s nine reference populations (Sub-Saharan Africa, Horn of Africa, North Africa, Middle East, Europe, South/Central Asia, East Asia, and East and West Greenland). We tested the performance of GenoGeographer with the Admixture Module on AIM profiles of 3548 individuals assumed to belong to one of the reference populations. A total of 3387 (95.5 %) profiles were assigned to one or more of the reference populations, either a single population or an admixture of two or more populations, while 161 (4.5 %) profiles were not assigned to any reference population or admixtures thereof. For 1486 AIM profiles with no reference population of origin in GenoGeographer, the rejection rate was more than 70 % for AIM profiles from North and South America and less than 20 % for those from Central, North, and Northeast Asia.     

"Biological identikit": Development of a SNPs-panel for the analysis of forensic DNA phenotyping and ancestry

Personal identification in mass disasters and in crimes is essential for humanitarian, ethical and legal reasons. In these contexts, when individuals cannot be identified by standard forensic DNA analysis, the Forensic DNA Phenotyping and the analysis of the biogeographical ancestry could help. The aim of this study was to evaluate the potential of a new panel of 891 SNPs in predicting phenotypic traits and biogeographical origin to create a “biological identikit”. In addition to fresh biological material, old evidence found at the crime scene or extracted and long-term stored DNA were tested with 41 SNPs for phenotyping and 850 SNPs for ancestry. All the SNPs were successfully incorporated into a single two-step multiplex PCR reaction using the IonAmpliSeq ™ Library Plus and applied for massive parallel sequencing with the Ion S5 platform using up to 0.05 ng/µL of DNA. The analysis of the results was carried out with an in-house predictive algorithm and consulting 20 population databases. By comparing the results obtained with identikit or video-photographic surveys, it was possible to predict phenotype and ancestry with an accuracy greater than 90%. While these new markers cannot identify a specific individual, they can be a valuable investigative tool.     

湖北地区汉族人群24个 Y-STR基因座遗传多态性研究

目的 对湖北汉族人群24个Y-STR基因座多态性进行调查,并获得相关的基础遗传学数据.方法 应用AGCU Y24 STR荧光标记复合直接扩增系统及3130XL型DNA测序仪,对湖北地区320对已确定父子关系的640个男性个体血样进行24个Y-STR检测分型.结果 在320名父亲男性个体中,在DYS391、DYS389工、DYS439、DYS389Ⅱ、DYS438、DYS449、DYS456、DYS458、DYS437、DYS635、DYS448、Y-GATA-H4、DYS447、DYS19、DYS392、DYS522、DYS393、DYS388、DYS390、DYS444基因座在湖北地区汉族人群分别检出4～17个等位基因,DYS527a/b检出45个等位基因组,DYS385a/b检出57个等位基因组,各基因座基因多样性最低为0.3838,最高为0.9650;并检出320种单倍型.比对320对父子Y-STR分型,在7680次基因遗传传递中,在DYS449、DYS527、DYS444、DYS389Ⅱ、DYS447、DYS522、DYS385、Y-GATA-H4等10个基因座中检出16个突变,突变率为1.5625‰～1.5653％,平均突变率为2.0833‰;等位基因增加突变与等位基因减少突变比为1∶1.结论 24个基因座单倍型在湖北地区汉族人群中具有丰富的遗传多态性,其数据对法医学应用、Y-STR数据库建设和群体遗传学等研究应用具有重要意义.