Evaluation of 19 short tandem repeat markers for individualization of Papaver somniferum

Papaver somniferum, commonly known as opium poppy, is the source of natural opiates, which are used as analgesics or as precursors in the creation of semi-synthetic opioids such as heroin. An increase in opioid addiction in the United States has resulted in high rates of illicit opioid use and overdoses. It has recently been shown that P. somniferum DNA suitable for genetic analysis can be recovered from heroin samples. The development of a comprehensive genetic individualization tool for opium poppy could serve to link cases and strengthen programs such as the Drug Enforcement Administration’s (DEA) Heroin Signature Program, which seeks to combat rising opioid use.The purpose of this study was to develop a quantitative real-time PCR (qPCR) method for the quantification of opium poppy DNA, compare three commercial DNA extraction kits for their ability to isolate DNA from poppy seeds, and evaluate nineteen opium poppy short tandem repeat (STR) markers for their use in a forensic identification panel. Such a panel could be used for individualizing samples and determining the geographic origin in heroin or poppy seed tea cases. The qPCR method was proven to be reproducible and reliable, specific for P. somniferum, and sensitive enough for forensic case-type samples. Of the three kits tested, the nexttec™ one-step DNA Isolation Kit for Plants was the optimal method and facilitated rapid extraction of DNA from poppy seeds. The majority of evaluated STR primer sets were unreliable or had low discriminatory power, limiting their use for individualization of poppy samples. A six-locus STR multiplex was developed and evaluated according to Scientific Working Group on DNA Analysis Methods (SWGDAM) and International Society of Forensic Genetics (ISFG) guidelines, including the use of a sequenced allelic ladder. The multiplex was found to have low discriminatory power, with greater than two-thirds of samples analyzed having just two different genotypes. The multiplex was determined to be unsuitable for individualization; however, a genotype map was developed as a proof of concept that these markers may be useful for determining the biogeographical origin of samples. Searching the poppy genome for new STR markers and developing new primer sets may be necessary for the creation of a powerful genetic tool for the individualization of P. somniferum.     

An ontology-based approach for the reconstruction and analysis of digital incidents timelines

Due to the democratisation of new technologies, computer forensics investigators have to deal with volumes of data which are becoming increasingly large and heterogeneous. Indeed, in a single machine, hundred of events occur per minute, produced and logged by the operating system and various software. Therefore, the identification of evidence, and more generally, the reconstruction of past events is a tedious and time-consuming task for the investigators. Our work aims at reconstructing and analysing automatically the events related to a digital incident, while respecting legal requirements. To tackle those three main problems (volume, heterogeneity and legal requirements), we identify seven necessary criteria that an efficient reconstruction tool must meet to address these challenges. This paper introduces an approach based on a three-layered ontology, called ORD2I, to represent any digital events. ORD2I is associated with a set of operators to analyse the resulting timeline and to ensure the reproducibility of the investigation.     

Identifying management factors for digital incident responses on Machine-to-Machine services

This paper presents a recent case study about how South Korea has modified the way it addresses digital incidents. To determine the best approach to mission-critical instances, the Multilateral Joint Analysis (MJA) model was used as an enhanced two stage process. The Delphi method and Structural Equation Model (SEM) were employed to determine the final model. This process established a governance mechanism that uses measurable control variables and is presently in use in mission critical services to protect against digital incidents.     

我国法医物证鉴定领域标准化问题及对策研究

标准化体系可以提高法医物证鉴定的质量，提高鉴定的公信力。法医物证鉴定标准化是开展鉴定业务、推广DNA新技术和我国法律的要求。标准化体系的建设和完善需要集思广益、群策群力，需要加强部门及地区之间合作交流，做好研制、培训和执行标准化文件的工作。标准化不能代替法庭审查，鉴定意见书仍需要法庭质证。     

Distribution of Y chromosomal STRs loci in Mayan and Mestizo populations from Guatemala

In this study, a sample of 225 Guatemalan males, comprising 115 Mestizo-Guatemalan and 110 Mayan-Guatemalan, was typed for 17 Y-short tandem repeats (STRs) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, YGATA_H4.1 and DYS385a/b). The haplotype diversity (H = 1) and discrimination capacity (96.86%) were calculated. Analysis of molecular variance (AMOVA) demonstrated a low but significant interpopulation differentiation when compared with the results obtained when we confront the Mestizo and Mayan populations with the European populations.Furthermore, the genetic variability and differences among the American, African, Asian, and European populations were analyzed with the software Statistica 9.1. In addition, the genetic distances were also calculated using other published data. Reynolds and Slatkińs genetic distance was visualized using the multidimensional scaling (MDS) analysis. All the analysis performed locates the Mayan population next to the Native American population, while Guatemalan-Mestizo population was found to be between these populations and the European population, similar to other Mestizo one.The implementation of the estimation of individual ancestry proportions of the whole population sample showed the presence of two well-differentiated population groups.     

身高推断的法医学研究进展CSCD

个体身高推断是法医人类学个体识别的重要内容之一,目前常借助直接测量或放射学技术收集一定群体的四肢长骨、不规则骨、体表解剖标志的数据建立回归方程来实现。由于人口流动性的增加、人类体质整体提高的影响以及种族和地区间的差异,身高推断的研究应成为常规性研究。本文对不同身高推断方法进行回顾性综述,简要阐述各方法的优缺点,并展望身高推断的研究方向。     

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.     

Probabilistic genotyping of single cell replicates from complex DNA mixtures recovers higher contributor LRs than standard analysis

DNA mixtures are a common source of crime scene evidence and are often one of the more difficult sources of biological evidence to interpret. With the implementation of probabilistic genotyping (PG), mixture analysis has been revolutionized allowing previously unresolvable mixed profiles to be analyzed and probative genotype information from contributors to be recovered. However, due to allele overlap, artifacts, or low-level minor contributors, genotype information loss inevitably occurs. In order to reduce the potential loss of significant DNA information from donors in complex mixtures, an alternative approach is to physically separate individual cells from mixtures prior to performing DNA typing thus obtaining single source profiles from contributors. In the present work, a simplified micro-manipulation technique combined with enhanced single-cell DNA typing was used to collect one or few cells, referred to as direct single-cell subsampling (DSCS). Using this approach, single and 2-cell subsamples were collected from 2 to 6 person mixtures. Single-cell subsamples resulted in single source DNA profiles while the 2-cell subsamples returned either single source DNA profiles or new mini-mixtures that are less complex than the original mixture due to the presence of fewer contributors. PG (STRmix™) was implemented, after appropriate validation, to analyze the original bulk mixtures, single source cell subsamples, and the 2-cell mini mixture subsamples from the original 2–6-person mixtures. PG further allowed replicate analysis to be employed which, in many instances, resulted in a significant gain of genotype information such that the returned donor likelihood ratios (LRs) were comparable to that seen in their single source reference profiles (i.e., the reciprocal of their random match probabilities). In every mixture, the DSCS approach gave improved results for each donor compared to standard bulk mixture analysis. With the 5- and 6- person complex mixtures, DSCS recovered highly probative LRs (≥10²⁰) from donors that had returned non-probative LRs (<10³) by standard methods.     

Attitudes towards police use of consumer/private DNA databases in investigations

Consumer DNA products, such as databases that allow the public to explore familial relationships, have recently been used by police to assist in investigations. This has moved the collection of DNA used in criminal investigations away from the limitations of criminal databases and has opened up ethical concerns regarding privacy and consent. This study explored public attitudes and support towards police use of consumer DNA databases in investigations to assess whether different crime types or moral and attitude alignments influenced the level of public support of police using these consumer products. An international survey of 438 adults, using theory and scales pertaining specifically to retributive punishment and attitudes towards law, courts and police, found that moral alignment and attitudes did influence the level of public acceptability towards police usage of these techniques and that support did vary based on crime type. This research found that higher levels of public support was given for the most serious case types explored (sexual assault and homicide). Participant support for police access to private DNA databases by case type was as follows; 83.5% for sexual assault, 83.2% for homicide, 85.2% for identifying unidentified human remains, 62.8% for robbery and 58.9% for illicit drug related cases. Small to medium effects sizes were observed for these results. Although these findings provided context towards public attitudes, further research specific to international attitude differences and variance between serious crime types and public acceptability could further develop these findings.