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Current analysis of forensic DNA stains relies on the probabilistic interpretation of bulk-processed samples that represent mixed profiles consisting of an unknown number of potentially partial representations of each contributor. Single-cell methods, in contrast, offer a solution to the forensic DNA mixture problem by incorporating a step that separates cells before extraction. A forensically relevant single-cell pipeline relies on efficient direct-to-PCR extractions that are compatible with standard down- stream forensic reagents. Here we demonstrate the feasibility of implementing single-cell pipelines into the forensic process by exploring four metrics of electropherogram (EPG) signal quality—i.e., allele detection rates, peak heights, peak height ratios, and peak height balance across low- to high-molecular-weight short tandem repeat (STR) markers—obtained with four direct-to-PCR extraction treatments and a common post-PCR laboratory procedure. Each treatment was used to extract DNA from 102 single buccal cells, whereupon the amplification reagents were immediately added to the tube and the DNA was amplified/injected using post-PCR conditions known to elicit a limit of detection (LoD) of one DNA molecule. The results show that most cells, regardless of extraction treatment, rendered EPGs with at least a 50% true positive allele detection rate and that allele drop-out was not cell independent. Statistical tests demonstrated that extraction treatments significantly impacted all metrics of EPG quality, where the Arcturus® PicoPure™ extraction method resulted in the lowest median allele drop-out rate, highest median average peak height, highest median average peak height ratio, and least negative median values of EPG sloping for GlobalFiler™ STR loci amplified at half volume. We, therefore, conclude the feasibility of implementing single-cell pipelines for casework purposes and demonstrate that inferential systems assuming cell independence will not be appropriate in the probabilistic interpretation of a collection of single-cell EPGs.

The knowledge of the ancestry of an unknown individual from forensic DNA may provide important information for law enforcement investigation. This information can be acquired from biological traces by means of massive parallel sequencing (MPS) technologies and developed arrays of ancestry informative DNA markers (AIM panels). Development of forensic AIM panels takes two steps: (1) obtainment of information on DNA polymorphism of individuals from different populations; (2) selection of polymorphic DNA markers (autosomal, Y-, X-chromosomal) and their validation. The necessity of keeping medical secrecy for the protection of human rights may limit the usage of ancestry informative markers suitable for forensic needs if they are also associated with genetic diseases and physical traits. The present article deals with the analysis of published strategies for selecting markers capable of differentiating populations to design a panel of ancestry informative markers and applying it in forensic analysis in the Republic of Belarus.

Contamination and degradation are known challenges for reliable genotyping, since they can cause, among other problems, false microsatellite profiles. In this study we described a method to decrease the proportion of false microsatellite profiles from fish scale samples of endangered allis shads (Alosa alosa) from a reintroduction program, where cross-contamination with DNA from other individuals and potentially degradation of samples occurred. To maximize the portion of reliably measurable results, we modified and combined two known approaches—thresholds used in forensic DNA analyses and a multiple-tubes approach. This combined approach increased reliable microsatellite profiles compared with single approaches. The forensic thresholds and the multiple-tubes approach increased the measurable results from 55 to 67% and 75%, respectively, whereas the combined approach accomplished an increase to 90%. This illustrates the potential of the combined approach for other studies with comparable problems or sample material.

Forensic DNA phenotyping (FDP) based on massive parallel sequencing (MPS) is an emerging technique within forensic genetics that enables the prediction of an individual's externally visible characteristics (EVCs) from DNA. Because of its achievements, FDP has become one of the most useful additional tools for aiding police investigations to narrow down the investigative pool in different types of forensic cases. Eye, hair and skin colour can now be predicted reliably and with practically useful accuracy. However, FDP has not yet been routinely implemented in the forensic science field due to, principally, the lack of complete genetic knowledge of pigmentation and facial traits and the lower predictability of intermediate phenotypes. Furthermore, in some countries its application has given rise to a number of ethical, social and legal issues, the latter being the most restrictive barrier to the implementation of FDP.

A impunidade tem despontado como um dos principais motivos do aumento da criminalidade no Brasil, principalmente devido à dificuldade dos processos investigativos em apontar a autoria de delitos. A indisponibilidade e a falta de transparência de dados da segurança pública e a alta taxa de subnotificação nos registros oficiais são alguns entraves que dificultam a avaliação da eficiência das políticas de segurança pública. Para o agravamento da situação, amostras coletadas em locais de crime pela Perícia Criminal podem não ser prontamente armazenadas nos bancos de DNA forense, ou quando o são, na maioria das vezes, não se obtém perfil genético compatível com os já cadastrados, diminuindo, assim, os índices nacionais de elucidação de autoria dos crimes. Dessa forma, o objetivo do artigo é apresentar um histórico sobre a implementação e evolução dos bancos de dados de perfis genéticos no Brasil. O processo de construção do banco de dados de DNA forense demonstra um avanço na qualidade das investigações policiais, encaixando-se perfeitamente como meio de prova no processo penal, somando-se às demais evidências necessárias à persecução penal. As técnicas de identificação baseadas na análise do DNA estão cada vez mais sendo empregadas no Brasil em amostras relacionadas a vestígios biológicos coletados em locais de crime, porém longe do patamar alcançado em países como os EUA e Reino Unido, que possuem milhões de perfis genéticos em seus bancos de dados, o que reflete nos seus altos índices de elucidação de crimes.

Background Forensic DNA phenotyping has gained momentum in the recent past due to the prediction of externally visible characters (EVCs) from the biological sample. The most common phenotypes like eye, hair, and skin color are predicted from the biological samples using a web-based system called IrisPlex. Based on six genetic SNPs, the IrisPlex system is developed and validated for its prediction accuracy in diverse ethnic groups worldwide. In previous studies, this system proved to have significant prediction accuracy. The EVCs vary substantially based on different geographical locations. Hence, the objective of this study was to validate the accuracy of the IrisPlex system in predicting the eye colors in the Iraqi population. Methods Six genetic single-nucleotide polymorphisms SNPs (HERC2-rs12913832, OCA2- rs1800407, SLC24A4-rs12896399, SLC45A2- rs16891982, TYR-rs1393350, and IRF4- rs12203592) in 58 Iraqi subjects were performed using Sequenom MassARRAY Genotyping. According to Liu et al., a predicted probability of 0.7 was considered as the threshold. Results Participants in this study of brown color were observed in 44.83%, intermediate in 43.1%, and blue in 12.07%. Completely predictive accuracy is obtained in 1; we observed the AUC at threshold 0.7 was 0.91 for brown, 0.79 for blue, and 0.60 for intermediate eye color. The sensitivity was 42.85% for blue, 0% for intermediate eye color, and 100% for brown-colored eye. Specificity was 100% for blue, 100% for intermediate, and 78.13% for brown eye color. Conclusion Hence, it was concluded that the prediction accuracy of the IrisPlex system for blue and brown color eye in the Iraqi population is significant in the studied population size. However, a pivotal study with larger sample size is required to represent the prediction accuracy of the IrisPlex system in the whole Iraqi population.

Increasingly in courts, the source of forensic DNA trace evidence is not challenged by the defence. Instead, the issue relates to how the suspect’s DNA got to the crime scene, suggesting it arrived...

Forensic DNA phenotyping (FDP) encompasses a set of technologies aimed at predicting phenotypic characteristics from genotypes. Advocates of FDP present it as the future of forensics, with an ultimate goal of producing complete, individualised facial composites based on DNA. With a focus on individuals and promised advances in technology comes the assumption that modern methods are steadily moving away from racial science. Yet in the quantification of physical differences, FDP builds upon some nineteenth- and twentieth-century scientific practices that measured and categorised human variation in terms of race. In this article I complicate the linear temporal approach to scientific progress by building on the notion of the folded object. Drawing on ethnographic fieldwork conducted in various genetic laboratories, I show how nineteenth- and early twentieth-century anthropological measuring and data-collection practices and statistical averaging techniques are folded into the ordering of measurements of skin color data taken with a spectrophotometer, the analysis of facial shape based on computational landmarks and the collection of iris photographs. Attending to the historicity of FDP facial renderings, I bring into focus how race comes about as a consequence of temporal folds.

Mixture analysis of complex forensic DNA mixtures can identify multiple individuals who cannot be excluded using massively parallel sequencing (MPS) with single-nucleotide polymorphism (SNP...

Background: Miao people are an officially recognised ethnic group living in southwest China, but have seldom been studied genetically, especially with respect to mtDNA data.Aim: To investigate the sequences and haplogroups of the mtDNA control region in a typical Miao population, with the aim of providing a good start for the expansion of the East Asian mtDNA reference database for forensic DNA analysis.Subjects and methods: We analysed 203 Miao individuals, looking at mtDNA control region sequences. We calculated and illustrated the haplotype frequencies, haplogroup distribution and pairwise Fst values between the Miao and six other worldwide populations to explore genetic polymorphisms and population relationships.Results: We observed 121 haplotypes with corresponding frequencies ranging from 0.0049 to 0.0690 in the Miao population. All the samples were assigned to 71 different haplogroups. The haplotype diversity and the random match probability were estimated to be 0.9844 and 0.0204, respectively. The pairwise Fst values and associated p values among seven populations suggest that the Miao population has significant differences to the other six populations, and is relatively isolated compared with them.Conclusions: Our results suggest that frequency estimates for mtDNA haplotypes in Miao ethnic groups should be determined independently rather than being pooled with other populations.

Ramos and Gonzalez-Rodriguez introduce the concept of calibration in order to determine whether a system of evidence presentation is a reliable assessor of evidential weight. In this paper, we appl...

The Huaxia™ Platinum Kit for short tandem repeat (STR) amplification was designed to meet the needs of the rapidly growing Chinese forensic database. This PCR multiplex allows simultaneous amplification of the following autosomal loci: D3S1358, vWA, D16S539, CSF1PO, TPOX, D8S1179, D21S11, D18S51, Penta E, D2S441, D19S433, TH01, FGA, D22S1045, D5S818, D13S317, D7S820, D6S1043, D10S1248, D1S1656, D12S391, D2S1338, Penta D and the gender-identification markers Yindel, and AMEL. The Huaxia™ Platinum Kit enables direct amplification from blood and buccal samples stored on treated and untreated paper, and features an optimized PCR protocol that yields time to results in less than 45 min. Developmental validation testing followed SWGDAM guidelines and demonstrated that this assay produces reproducible and accurate results. Studies on 798 individuals in 4 major Chinese ethnic groups produced highly concordant results with other commercially available STR genotyping kits. The validation results demonstrate that the Huaxia™ Platinum Kit is a robust and reliable identification system for forensic DNA databasing applications.

Cartridges, bullets, and casings (CBCs) are commonly recovered after shooting incidents and could provide valuable DNA information from touch DNA that has been left behind during handling of bullets and loading of guns. Direct PCR, in which the DNA extraction and quantification steps are bypassed, has been shown to provide comparable and sometimes better results from touch DNA and trace DNA samples. Here, direct PCR was applied to touch DNA retrieved from bullet casings from three ammunition types and guns. The results were evaluated to determine whether the technique should be recommended as a standard operating protocol for forensic DNA analysts. Three experiments were carried out to investigate the following: the effect of firing bullets on DNA deposited on bullet casings; the effect of gun and ammunition types on short tandem repeat (STR) profile quality; and the feasibility of using direct PCR in real-world cases via typing of mock casework samples. DNA extraction resulted in a loss of about 40% of DNA originally deposited, and firing a bullet reduced the amount of DNA recovered by 27%. Using the direct PCR protocol, conventional extraction protocol, and dilution protocol on touch DNA from fired bullet casings, we recovered means (and 95% credible intervals), respectively, of 11.1 (7.9–13.9), 5.6 (3.0–7.7), and 2.3 (0.2–4.0) alleles. No statistical difference in alleles recovered was observed between different calibers of ammunition fired from three guns (9 mm, 7.62 mm, and 5.56 mm from Glock Model 19, AK47, and Tavor T-21, respectively). As expected, mixed DNA profiles were observed in 40% of the mock casework samples, in which guns were shared between volunteers. This study showed that direct amplification of touch DNA from bullet casings improved STR profiles. As direct PCR is quicker, cheaper, and resulted in more alleles recovered, forensic DNA analysts may benefit from using direct PCR.

Crown Copyright © 2019 Published by Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (March 2019) in accordance with the publisher’s archiving policy, Standard practice in forensic science is to compare a person of interest’s (POI) reference DNA profile with an evidence DNA profile and calculate a likelihood ratio that considers propositions including and excluding the POI as a DNA donor. A method has recently been published that provides the ability to compare two evidence profiles (of any number of contributors and of any level of resolution) comparing propositions that consider the profiles either have a common contributor, or do not have any common contributors. Using this method, forensic analysts can provide intelligence to law enforcement by linking crime scenes when no suspects may be available. The method could also be used as a quality assurance measure to identify potential sample to sample contamination. In this work we analyse a number of constructed mixtures, ranging from two to five contributors, and with known numbers of common contributors, in order to investigate the performance of using likelihood ratios for mixture to mixture comparisons. Our findings demonstrate the ability to identify common donors in DNA mixtures with the power of discrimination depending largely on the least informative mixture of the pair being considered. The ability to match mixtures to mixtures may provide intelligence information to investigators by identifying possible links between cases which otherwise may not have been considered connected.

As an important aspect of epigenetics, DNA methylation has been proven to be suitable for forensic DNA analysis. By detecting changes in DNA methylation, it is desirable to construct a model of age patterns associated with it to infer the age of the individual. The hTERT gene methylation is closely related to tumors, but there are few reports on the relationship between hTERT gene promoter methylation and age. In this study, we utilized the methylation-specific polymerase chain reaction and real-time PCR (relative quantification and absolute quantification) approach to explore the connection between hTERT DNA methylation and age prediction. We fit three models for age prediction based on methylation assay for 90 blood samples from donors aged 1–79 years old. Among them, the model of absolute quantification of real-time enabled the age prediction with R2 = 0.9634. We verified the linear regression model with a validation set of 30 blood samples where prediction average error was 4.29 years. Generally, this reliable method improves the DNA methylation analysis of forensic samples.

Modern interpretation strategies typically require an assignment of the number of contributors (N) to a DNA profile. This can prove to be a difficult task, particularly when dealing with higher order mixtures or mixtures where one or more contributors have donated low amounts of DNA. Differences in the assigned N at interpretation can lead to differences in the likelihood ration (LR). If the number of contributors cannot reasonably be assigned, then an interpretation of the profile may not be able to be progressed. In this study, we investigate mixed DNA profiles of varying complexity and interpret them altering the assigned N. We assign LRs for true- and non- contributors and compare the results given different assignments of N over a range of mixture proportions. When a component of a mixture had a proportion of at least 10%, a ratio of at least 1.5:1 to the next highest component, and a DNA amount (as determined by STRmix™) of at least 50 rfu, the LR of the component for a true contributor was not significantly affected by varying N and was therefore suitable for interpretation and the assignment of an LR. LRs produced for minor contributors were found to vary significantly as the assigned N was changed. These heuristics may be used to identify profiles suitable for interpretation.

Review article presents essential information on DNA databases, forensic genomics for human identification and suspect characteristics. Author reports the essential information on the topic of forensic DNA databases and data processing. DNA databases are important tools for the improvement of performance of the security organizations and services with a final goal of national security enhancement.

Ancestry informative SNPs (AISNPs) are genetic variants that exhibit substantially different frequencies between populations from different geographical regions; thus, they can provide some valuable information regarding samples and be used in predicting an individual's ancestry origin. In this study, we selected the potentially best SNPs from our previous study with genome-wide high-density SNP data in mainland Chinese Uygur and Han populations and investigated the allele distribution patterns and genetic information of AISNPs with a mass spectrometry-based SNP genotyping panel. Mass spectrometry-based detection technology offers the opportunity to analyze forensic DNA samples and obtain SNP variants with accuracy and ease. The panel can distinguish and cluster Han and Uygur populations and is suitable for human identification and parentage testing in the two populations. Heatmap, PCA, and Structure analyses indicated that the ideal 64 AISNPs can collectively provide additional information on differences among populations from East Asia, South Asia, Europe and Africa. Additionally, the results proved that the Uygur population is the admixture of East Asia and Europe.

Law enforcement is moving from targeted forensic DNA analysis to more extensive use of genomics in support of criminal investigations and for related purposes, such as the identification of human r...

Evaluative reporting provides a balanced approach to evidence interpretation. The use of evaluative reporting in forensic DNA analysis is common practice and well understood in Australia and New Ze...

As DNA sequencing technology advances, in-field genome sequencing capabilities are being explored, utilized and validated. With the assistance of such advances, forensic DNA processing is at the da...

It has been advocated before that appearance prediction of unknown suspects from crime scene DNA, in thecontext of Forensic DNA Phenotyping (FDP), is mostly suitable for single source DNA samples, whereas FDP fromDNA mixtures to which more than one person contributed, is viewed challenging. With this report on a murdercase, we practically demonstrate the feasibility of appearance DNA prediction of an unknown suspect from amixed crime scene trace, to which the unknown suspect and the known victim had contributed. From this twoperson DNA mixture, we successfully predicted eye, hair and skin color of the unknown suspect with theHIrisPlex-S system by applying targeted massively parallel sequencing (MPS). We argue that at least three factorsbenefit appearance DNA prediction of unknown suspects from mixed crime scene traces, which were met in thismurder case: i) SNP genotype knowledge from reference DNA analysis for one of the two persons in the mixture(here the known victim), ii) about equal DNA contributions by both donors to the mixed crime scene stain, andiii) the use of MPS allowing quantitative SNP analysis. Moreover, we show that additionally analyzing animalDNA in this mixed crime scene trace provides further investigative information. We envision that the investigative DNA strategy that we applied here for analyzing a two-person mixed crime scene trace in a murder case,will be applied in the future to more criminal cases with two-person DNA mixtures, for instance sexual assaultcases.

Stomach content analyses are a valuable tool in human forensic science to interpret perimortem events. While the identification of food components of plant and animal origin has traditionally been conducted by macro- and microscopical approaches in case of incomplete digestion, molecular methods provide the potential to increase sensitivity and taxonomic resolution. In particular, DNA metabarcoding (PCR-amplification and next generation sequencing of complex DNA mixtures) has seen a rapid growth in the field of wildlife ecology to assess species’ diets from faecal and gastric samples. Despite clear advantages, molecular approaches have not yet been established in routine human forensics to investigate the last meal components of deceased persons. In this pilot study we applied for the first time a DNA metabarcoding approach to assess both plant and vertebrate components of 48 human stomach content samples taken during medicolegal autopsies. We obtained a final dataset with 34 vertebrate and 124 vegetal unique sequences, that were clustered to 9 and 33 operational taxonomic units (OTUs), respectively. Our results suggest that this approach can provide crucial information about circumstances preceding death, and open promising perspectives for biomedical dietary surveys based on digested food items found in the gastrointestinal tract.

Paternity tests is often faced with the unavailability of information from the father, mother, or child as a comparison in forensic DNA examination process. Therefore, comparisons with information from close family lines are needed, for example from the victim's siblings or the perpetrator if there are no comparisons from parents or siblings. This study was conducted by the Human Genetic Study Group of Airlangga University in its campus from January to April 2020. The aim of the study was to analyze the use of kinship analysis in paternity test through STR CODIS examination on siblings. This was an observational laboratory study with a temporary design. DNA sample extraction level and purity results were measured with the mean DNA sample level of 675±5.35ng/µL, while the purity values ranged from 1.05 to 1.86. The paternity test principle is based on comparison process between the parents’ alleles with the child’s alleles. However, if the parents’ alleles are not available, the siblings’ alleles can be used as a comparison for identification purpose, which is known as kinship analysis. Statistically, full siblings have a 2 alleles accuracy probability of [0.25] 25%, which was the same as not having the same allele or 0 allele, while 1 allele accuracy reached 50%. All CODIS STR loci had the highest percentage of 2 allele sharing. Therefore, it is recommended to use sibling or kinship analysis if both parents are absent.

Analytical techniques such as DNA profiling are widely used in various fields, including forensic science, and novel technologies such as direct polymerase chain reaction (PCR) amplification are continuously being developed in order to acquire DNA profiles efficiently. However, non-specific amplification may occur depending on the quality of the crime scene evidence and amplification methods employed. In particular, the ski-slope effect observed in direct PCR amplification has led to inaccurate interpretations of the DNA profile results. In this study, we aimed to reduce the ski-slope effect by using dimethyl sulfoxide (DMSO) in direct PCR. We confirmed that DMSO (3.75%, v/v) increased the amplification yield of large-sized DNA sequences more than that of small-sized ones. Using 50 Korean buccal samples, we further demonstrated that DMSO reduced the ski-slope effect in direct PCR. These results suggest that the experimental method developed in this study is suitable for direct PCR and may help to successfully obtain DNA profiles from various types of evidence at crime scenes.

This article is about the governance of expectations of forensic DNA phenotyping (FDP) innovations in Germany used for the prediction of human externally visible traits such as eye, hair, and skin color, as well as biological age and biogeographic ancestry. In 2019, FDP technologies were regulated under the label “extended DNA analysis”. We focus on the expectations of members of the forensic genetics’ community in Germany, in anticipation and response to those of regulators who advocated for such technologies. Confronted with regulators’ expectations of omnipotent technologies and the optimistic promise that they will enhance public security, forensic geneticists responded with attempts to adjust such expectations, specifying limits and risks, along with a particular logic sorting matters of concern. We reflect on how forensic geneticists’ govern expectations through forms of distributed anticipatory governance, delimiting their obligations, and distributing accountability across the criminal justice system., This work was supported by H2020 European Research Council [grant number 648608] and Fundação para a Ciência e a Tecnologia [grant number CEECIND/03611/2018/CP1541/CT0009].

First Published June 4, 2020., Forensic DNA phenotyping isa genetic technology that might be used in criminal investigations. Based on DNA samples of the human bodyfound at crime scenes, it allows to infer externally visible characteristics (such as eye, hair and skin colour)and continental-based biogeographical ancestry.By indicating the probable visible appearance of a criminal suspect, forensic DNA phenotyping allows to narrowdown the focus of a criminal investigation.In this article, drawing on interviews with forensic geneticists, we explorehow their narratives translate contemporary focus on criminalmolecularizedbodies. We propose the concept of (de)materialization to approach three aspects of the forensic geneticists’ views. The first regards consideringbodies as mutable entities. The second relates to socially contingent meanings attributed to bodies. The third regardsto controversies surrounding data reliability.Byreflecting upon the(de)materialization of criminal bodies, forensic geneticists juxtapose the defence and unsettling of forensic DNA phenotyping claims., This work has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Consolidation grant, agreement No. [648608]) within the project “EXCHANGE – Forensic geneticists and the transnational exchange of DNA data in the EU: Engaging science with social control, citizenship and democracy”, which is led by Helena Machado and hosted at the Communication and Society Research Centre (CECS), Institute for Social Sciences of the University of Minho, Portugal.

On the morning of October 19, 2004, an eight-year-old boy and a 56-year-old woman were stabbed to death on an open street in the city of Linko center dot ping, Sweden. The perpetrator left his DNA at the crime scene, and after 15 years of various investigation efforts, including more than 9000 interrogations and mass DNA screening of more than 6000 men, there were still no clues about the identity of the unknown murderer. The successful application of investigative genetic genealogy (IGG) in the US raised the interest for this tool within the Swedish Police Authority. After legal consultations it was decided that IGG could be applied in this double murder case as a pilot case study. From extensive DNA analysis, including whole-genome sequencing and genotype imputation, DNA data sets were established and searched within both GEDmatch and FamilyTree DNA genealogy databases. A number of fairly distant relatives were found from which family trees were created. The genealogy work resulted in two candidates, two brothers, one of whom matched the crime scene samples by routine STR profiling. The suspect confessed the murders at the initial police hearing and was later convicted of the murders. In this paper we describe the successful application of an emerging technology. We disclose details of the DNA analyses which, due to the poor quality and low quantity of the DNA, required reiterative sequencing and genotype imputation efforts. The successful application of IGG in this double murder case exemplifies its applicability not only in the US but also in Europe. The pressure is now high on the involved authorities to establish IGG as a tool for cold case criminal investigations and for missing person identifications. There is, however, a continuous need to accommodate legal, social and ethical aspects as well. Funding Agencies|Swedish Research CouncilSwedish Research CouncilEuropean Commission; Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation

Recent scientific advancements in the field of genetics have fostered significant changes for the criminal justice system. Growing National DNA databases, public DNA databases, private direct-to-consumer (DTC) DNA testing companies, and improvements in next-generation sequencing (NGS) have resulted in effective methods for tracking down criminals and exonerating the innocent. While these recently discovered and profound techniques seem to provide benefits, their use in forensic detection has become subject to harsh legal opposition. Ultimately, should law enforcement be permitted to analyze DNA found at crime scenes and DNA that has accumulated in national, public, and private databases to aid in their investigations, or are individuals' privacy rights breached in the process?

Efficient sampling with swabs is crucial for optimal forensic DNA analysis. The DNA recovery is determined by the skill of the practitioner and the compatibility between the applied swab and the surface. Here we investigate the impact of swabbing technique and swab type on the DNA yield. Thirteen different swabs from four categories (cotton, flocked nylon, small foam and large foam) provided equal DNA yields for smooth/non-absorbing surfaces. Large foam swabs gave higher DNA recovery for an absorbing wood surface. Factorial design of experiments and ANOVA was applied to study swabbing techniques for cotton swabs. Two key factors for efficient sampling were found to be 1) holding the swab with an approximate 60 degrees angle against the surface and 2) to rotate the swab during sampling. For absorbing wood, it was beneficial to wet the swab heavily. The results of the factorial experiments were used to develop swabbing protocols for different surfaces. When ten experienced practitioners sampled according to these protocols, the DNA yield was increased for ridged plastic (around 1.25 times more DNA) and absorbing wood (2.2-6.2 times more DNA). For window glass, representing a smooth/nonabsorbing surface, sampling according to the protocol gave DNA yields equivalent to applying individual sampling techniques. The protocol lowered person-to-person variation for ridged plastic. In conclusion, we have developed instructive protocols for cotton swab sampling on three types of surfaces: smooth/non-absorbing, ridged/non-absorbing and smooth/absorbing. We believe that such swabbing protocols will streamline and simplify the training of new practitioners and improve sampling efficiency for invisible DNA residues in casework. Funding Agencies|Swedish Civil Contingencies Agency, Sweden

Forensic DNA profiling is used in various circumstances to evaluate support for two competing propositions with the assignment of a likelihood ratio. Many software implementations exist that tackle a range of inference problems spanning identification and relationship testing. We propose a flexible likelihood ratio framework that caters to inference problems in forensic genetics. The framework allows for investigation of the degree of support for the contribution of multiple persons to multiple samples allowing for persons to be related according to a pedigree, including inbred relationships. We explain how a number of routine as well as more complex problems can be treated within this framework.

Forensic characterization and genetic evaluation study in the 539 randomly selected unrelated adult healthy individuals belonging to the Central Indian population was undertaken. The study was performed using a multiplex of 27 Y-STRs incoporated in Yfiler™ Plus multiplex kit. Out of 539 samples, 6 samples were observed for large deletion and tri-allelic patterns, which were removed from the analysis, and out of 533 samples, a total of 507 haplotypes were found, and out of these haplotypes, 482 unique haplotypes were found in this piece of work. The forensically important parameters, i.e., gene diversity (GD) and discrimination capacity (DC), were found to be 0.669 and 0.951, respectively, for the tested Y STR loci. The genetic data of this study will enrich the Y STR data bank and being used as a potential tool for forensic DNA and various genetic studies.

Highlights • Biosafety measures in forensic laboratories are needed during the SARS-CoV-2 pandemic. • Protocols for sample handling and storage may need to be re-evaluated. • Negative effects of the SARS-CoV-2 pandemic on forensic casework and genetics research., The aggressive nature of the new SARS-2 corona virus now referred to as SARS-CoV-2 ; the seriousness and length of the period of infection; the fast and far-reaching transmissibility via liquid droplets that become air-borne when someone coughs, sneezes or speaks with increasing evidence to support actual airborne transmission; the presence of viral particles especially in body fluids and tissues, of viral positive individuals; and the persistence of the virus on different types of surfaces pose serious concerns for forensic practitioners, including forensic DNA analysts. Many forensic laboratories and law enforcement agencies need to address the inevitable changes that must be made in forensic DNA testing. In this article, we explore the effects of the COVID-19 pandemic on the collection, handling, storage and transport of biological samples for downstream DNA testing. This paper aims to open discussions on the urgency of balancing the need to conduct investigations in order to maintain public order with the requirements of effective biosafety protocols specifically formulated to protect human resources within the forensic science community.

Forensic DNA profiling is a standard method used in the attempt to identify deceased individuals. In routine investigations, and if available, the preferred sample type is usually blood. However, this requires the invasive re-opening of the body, days or weeks after the autopsy, which is undesirable in resource-constrained mortuary settings. Motivated by the ease of sampling as well as reduced health and safety risks, this study aimed to establish the success rate of generating a full DNA profile on first attempt from buccal swab lysates using a direct PCR approach. Buccal swab samples were collected from 100 unidentified deceased males, and were subjected to direct DNA profiling with use of the Promega PowerPlex® Y23 Kit. At the time of sample collection, these individuals had been stored for between 1 and 887 days. This study shows that full DNA profiles were initially obtained from 73% of samples, which constitutes the first empirical data pertaining to first time success rates of direct PCR from post-mortem buccal lysates. Further investigation of partial and failed DNA profiles using real-time PCR showed that samples did not contain PCR inhibitors, DNA was not degraded, but DNA concentration was particularly low. Repeating DNA profiling with increased lysate input and extra PCR cycles yielded an additional six full DNA profiles, resulting in an overall success rate of 79%. Overall, DNA profile success rate was not associated with the duration of storage (p = 0.387). Lastly, massively parallel sequencing with the ForenSeq™ Signature DNA Prep kit provided more informative profiles for three additional samples. These results indicate that blood should therefore remain the sample of choice in a post-mortem setting, yet buccal lysates hold potential to be optimised further, which may ease the human identification workflow.

Forensic DNA typing from touched or handled items in routine casework is increasing as the sensitivity of detection techniques improves. Our understanding of the cellular/acellular content of touch deposits and the origins of the DNA therein is still limited. This work explores the cellular content of rinses from washed and unwashed hands, as well as saliva, nasal and eye washes which could be sources of transferred DNA onto hands. Flow cytometry and microscopic examination were used to detect granularity, size and nucleic acid fluorescence data. Cellular content did not vary significantly within an individual, although some differences were observed between donors. Saliva contained populations of nucleated epithelia as well as smaller cells and debris, all positive for DNA. Hand rinses consisted almost entirely of anucleate corneocytes, many of which also stained positive for nucleic acids. These data raise questions about shed corneocyte DNA content previously assumed to be negligible.

Deconvolution of forensic DNA mixtures into their individual component DNA (geno)types is of great investigative value, though often complex and difficult. Two-person mixtures comprising a major and minor contributor are often easily interpreted although, when the DNA ratio of the two individuals is approximately equal (~1:1), deconvolution and interpretation becomes much more difficult. To address this issue, a physical separation of individual-, two- or three- cell subsamples prior to autosomal STR analysis was performed using a simplified micromanipulation technique paired with a decreased reaction volume and increased cycle number PCR. Using this method, single and multiple buccal epithelial cells were collected from a 1:1 two-person mixture (i.e. from individual 'A' and 'B') and directly amplified, omitting standard DNA extraction and purification steps. Single cell subsamples resulted in partial single-source profiles for both contributors while, in accordance with expectations of a quasi-binomial sampling schema, two- and three-cell subsamples resulted in single source informative partial profiles of individual A and individual B as well as complete consensus profiles, and equally mixed 1:1 (2-cell subsamples) and 2:1 (3-cell subsamples) admixed profiles of individual A and B.This proof-of-concept approach shows promise in permitting the DNA deconvolution of mixed samples where the individual contributors are present in similar amounts that would otherwise be difficult to interpret, resulting in an increase in evidentiary value. The subsampling approach can be readily investigated for DNA casework applications without additional investment in costly, new equipment, requiring only a stereo microscope and a tungsten needle.

There has been an increase in the number of laboratories and researchers adopting new sequencing technologies, known as next-generation sequencing (NGS). An understanding of the behaviour of NGS DNA profiles is needed to enable for the development of probabilistic genotyping methods for the interpretation of such profiles. In this work, we investigate NGS analyte signal variation, specifically heterozygous balance and stutter variability from profiles generated using the ForenSeq™ DNA Signature Prep Kit, DNA Primer Mix B. We also investigate additivity of analyte signals in NGS profiles for overlapping allelic and stutter signals originating from the same or different contributors. We describe models that can be used to inform a continuous method for the interpretation of DNA profiling data.

In casework there are often multiple mixed DNA profiles with a single unknown offender who is believed to be a contributor. Sometimes none of these profiles are individually informative enough to evaluate whether a person of interest (PoI) is a contributor. We propose a method that combines evidence across multiple mixtures to better resolve the genotype of a queried common donor. This method can also resolve genotypes of a queried non-common donor (i.e. unique to one profile), when other donors of that mixture have contributed to multiple samples. The approach has similarities with the analysis of replicate PCRs, with the difference being that we do not necessarily assume that all the contributors are the same across the evidential profiles, nor do we assume that parameters such as the mixture ratio are constant. Our method can be used to compute an LR for a PoI being the common contributor to multiple stains. It is also possible to interrogate a database of reference profiles to search for the queried donor (common or non-common). We show that the method can identify a queried contributor in cases where individual comparisons have limited capacity to discriminate between donors and non-donors, when some assumption(s) can be made about multiple contributors being from the same sources (queried or not).

DNA mixtures will have multiple donors under both the prosecution and alternate propositions when assigning a likelihood ratio for forensic DNA evidence. These donors are usually assumed to be unrelated to each other. In this paper, we make a small, preliminary examination of the potential effect of relaxing this assumption. We consider the simple situation of a two-person mixture with no dropout and a two-person major/minor mixture with dropout of the minor contributor. We make no adjustment for subpopulation effects. Mixtures were simulated under two assumptions: 1. that the donors were siblings 2. or that they were unrelated. Both unresolvable and major/minor mixtures were considered. We compared the likelihood ratio assuming sibship with the likelihood ratio assuming no relatedness. The LR for hypotheses assuming no relatedness is less than the LR assuming relatedness approximately 95% of the time when relatives are present in the mixture.

This article explores the fluid and flexible forms of constructing suspicion, which take shape in transnational governance of crime through forensic DNA databases. The empirical examples are the views of professionals engaged with the so-called Prüm system. This technological identification system was developed to enable DNA data exchange across EU Member States in the context of police and judicial cooperation to control cross-border crime and terrorism. We argue that suspicion is constructed through forms of deterritorializing and reterritorializing assumptions about criminality linked to the movements of suspect communities across the European Union. Transnational crime management is configured through narratives of global expansion of criminal mobility, technical neutrality of DNA identification and the reliance on criminal categorizations of particular national populations., Este trabalho recebeu financiamento do Conselho Europeu de Investigação (ERC) sob o programa de pesquisa e inovação da União Europeia Horizonte 2020 (Contrato N.º [648608]), no âmbito do projeto “EXCHANGE – Geneticistas forenses e a partilha transnacional de informação genética na União Europeia: Relações entre ciência e controlo social, cidadania e democracia” liderado por Helena Machado e sedeado no Centro de Estudos de Comunicação e Sociedade, Instituto de Ciências Sociais da Universidade do Minho (Portugal).

The study of DNA to predict externally visible characteristics (EVCs) and the biogeographical ancestry (BGA) from unknown samples is gaining relevance in forensic genetics. Technical developments in Massively Parallel Sequencing (MPS) enable the simultaneous analysis of hundreds of DNA markers, which improves successful Forensic DNA Phenotyping (FDP). The EU-funded VISAGE (VISible Attributes through GEnomics) Consortium has developed various targeted MPS-based lab tools to apply FDP in routine forensic analyses. Here, we present an evaluation of the VISAGE Basic tool for appearance and ancestry prediction based on PowerSeq chemistry (Promega) on a MiSeq FGx System (Illumina). The panel consists of 153 single nucleotide polymorphisms (SNPs) that provide information about EVCs (41 SNPs for eye, hair and skin color from HIrisPlex-S) and continental BGA (115 SNPs, three overlap with the EVCs SNP set). The assay was evaluated for sensitivity, repeatability and genotyping concordance, as well as its performance with casework-type samples. This targeted MPS assay provided complete genotypes at all 153 SNPs down to 125 pg of input DNA and 99.67% correct genotypes at 50 pg. It was robust in terms of repeatability and concordance and provided useful results with casework-type samples. The results suggest that this MPS assay is a useful tool for basic appearance and ancestry prediction in forensic genetics for users interested in applying PowerSeq chemistry and MiSeq for this purpose.

To answer the question “Are low likelihood ratios reliable?” requires both a definition of reliable and then a test of whether low likelihood ratios (LRs) meet that definition. We offer, from a purely statistical standpoint, that reliability can be determined by assessing whether the rate of inclusionary support for non-donors over many cases is not larger than expected from the LR value. Thus, it is not the magnitude of the LR alone that determines reliability. Turing’s rule is used to inform the expected rate of non-donor inclusionary support, where the rate of non-donor inclusionary support is at most the reciprocal of the LR, i.e. Pr(LR > x|Ha) ≤1/x. There are parallel concerns about whether the value of the evidence can be communicated. We do not discuss that in depth here although it is an important consideration to be addressed with training. In this paper, we use a mixture of real and simulated data to show that the rate of non-donor inclusionary support for these data is significantly lower than the upper bound given by Turing’s rule. We take this as strong evidence that low LRs are reliable.

Interlaboratory studies are a type of collaborative exercise in which many laboratories are presented with the same set of data to interpret, and the results they produce are examined to get a "big picture" view of the effectiveness and accuracy of analytical protocols used across participating laboratories. In 2005 and again in 2013, the Applied Genetics Group of the National Institute of Standards and Technology (NIST) conducted interlaboratory studies involving DNA mixture interpretation. In the 2005 NIST MIX05 study, 69 laboratories interpreted data in the form of electropherograms of two-person DNA mixtures representing four different mock sexual assault cases with different contributor ratios. In the 2013 NIST MIX13 study,108 laboratories interpreted electropherogram data for five different case scenarios involving two, three, or four contributors, with some of the contributors potentially related. This paper describes the design of these studies, the variations observed among laboratory results, and lessons learned.

This review analysed public perspective studies on forensic DNA retention in the United Kingdom and around the world. The studies generally show strong public support for the long-term or indefinite retention of DNA from convicts and suspects. There is considerable support for the retention of DNA from all or some arrestees and potentially the entire population. This was predicated upon the belief that forensic DNA databases have crime-solving abilities, which the public rate highly. In the UK, it was found that the current Protection of Freedoms Act 2012 regime is broadly representative of the recommendations of the surveyed British public. Nevertheless, the studies highlighted a gap in forensic DNA education among the public, suggesting that public views may not be well informed. Overall, there was clear evidence of privacy concerns and the potential misuse of DNA records among the public, with a significant number opposing the retention of DNA from the innocent. It was found that most of the studies were qualitative or non-representative of the relevant population, limiting the generalisation of the results. There was also limited studies among a representative sample of primary stakeholders who are well-informed or directly exposed to the benefits, challenges and risks associated with DNA retention. A research into stakeholders rating of different forensic DNA retention regimes is therefore highly recommended. This is important because the studies suggest divergent views among criminal justice professionals and other members of the public, with the former expressing expansive views and the latter expressing restrictive views. The primary stakeholder's survey will help establish whether the relevant safeguards have been put in place to protect both public security and individual interests.

A new rapid DNA solution, the RapidHIT ID, can accommodate two different sample cartridges, ACE, for the analysis of a single swab and EXT, for the analysis of DNA extracts. An efficient internal validation designed for low-throughput rapid DNA is described. An evaluation of the EXT sample cartridge is also described. Each cartridge generated profiles with sufficient data quality to meet CODIS eligibility in fewer than 120 min. The results exhibited 100% correlation when compared to conventional DNA typing methods. Precision, reproducibility, stochastic, mixture, and contamination experiments produced expected results. Sensitivity of the ACE sample cartridge was acceptable for buccal swab analysis. The sensitivity of the EXT sample cartridge is discussed. The ACE validation and the EXT evaluation utilized a minimalist, cost-saving, efficient design to generate a validated RapidHIT ID instrument capable of producing genetic profiles from both extracted forensic DNA samples and buccal swab samples within 120 min.

Forensic DNA analysis is dependent on comparing the known and the unknown. Expand the number of known profiles, and the likelihood of a successful match increases. Forensic use of DNA is mo...

Interpreting mixed DNA samples containing material from multiple contributors has long been considered a major challenge in forensic casework, especially when encountering low-template DNA (LT-DNA) or high-order mixtures that may involve missing alleles (dropout) and unrelated alleles (drop-in), among others. In the last decades, extraordinary progress has been made in the analysis of mixed DNA samples, which has led to increasing attention to this research field. The advent of new methods for the separation and extraction of DNA from mixtures, novel or jointly applied genetic markers for detection and reliable interpretation approaches for estimating the weight of evidence, as well as the powerful massively parallel sequencing (MPS) technology, has greatly extended the range of mixed samples that can be correctly analyzed. Here, we summarized the investigative approaches and progress in the field of forensic DNA mixture analysis, hoping to provide some assistance to forensic practitioners and to promote further development involving this issue.

When a morphologically separated skull and mandible are found in the same case context, the possibility of a match arises. Two criteria with which to determine a match are the rough articulation between the mandibular condyles and cranial base itself and, most importantly, the fit of the teeth. However, when there has been intravital or postmortem tooth loss, this important criterion is not available. To date, only Reichs (1989) has investigated further compatibility criteria to solve the question of putative commingling in a case where a mandible seemed to originate from a female, while all other bones originated from a male individual. In a different reported case (Preisler et al. 2017), a mandible seemed too big for a skull; DNA analysis, however, confirmed that both originated from the same female individual. To investigate the metric relationship between mandible and skull we measured the postmortem CT data records of 223 corpses (virtual skulls) in OsiriX© MD for the following linear parameters: bicondylar breadth (KDB), biradicular breadth (AUB), and bizygomatic breadth (ZYB). The indices KDB/ZYB and KDB/AUB were developed and used to define ranges for matches and mismatches. Furthermore, the intra-observer reliability for the method was assessed. An intraclass correlation coefficient of >0.99 for every parameter showed that the used measurements are highly reliable. The 2.5–97.5 percentile for the KDB/AUB index lay between 0.91 and 1.05, while the range for the KDB/ZYB index was between 0.87 and 1.00. Within these ranges, it is possible to roughly assess whether or not a mandible and skull might be compatible, even if this can only be verified by forensic DNA analysis. If an index value lies outside these ranges, it can be assumed that skull and mandible do not match. Future studies should include more samples from a broader population spectrum so that these metric relationships can be used for different populations.

The ABO blood group is considered to be one of the most important markers in forensic testing. Additionally, autosomal short tandem repeat (STR) genotyping continues to be recognized as the dominan...

Forensic geneticists have attempted to make the case for continued investment in forensic genetics research, despite its seemingly consolidated evidentiary role in criminal justice, by shifting the focus to technologies that can provide intelligence. Forensic DNA phenotyping (FDP) is one such emerging set of techniques, promising to infer external appearance and ancestry of an unknown person. On this example, I consider the repertoire of anticipatory practices deployed by scientists, expanding the concept to not only focus on promissory but also include epistemic and operational aspects of anticipatory work in science. I explore these practices further as part of anticipatory self-governance efforts, attending to the European forensic genetics community and its construction of FDP as a reliable and legitimate technology field for use in delivering public goods around security and justice. In this context, I consider three types of ordering devices that translate anticipatory practices into anticipatory self-governance.