Random Match Probability Research Articles

Empirically observed and predicted estimates of chance association: Estimating the chance association of randomly acquired characteristics in footwear comparisons

The power associated with demonstrating a linkage between footwear and an impression left at the scene of a crime is directly related to the perceived rarity of the shoeprint itself. When individualizing characteristics are present, their relative position, orientation, size and shape are examined and compared with known exemplars to establish the strength of the suspected linkage. However, the degree to which a feature might repeat by chance alone is less well documented in many pattern science fields, including forensic footwear analysis. To assess this chance, the mathematical similarity of more than 3.2 million pairwise RAC comparisons was performed, as a function of more than 72,000 RACs, collected from 1300 unrelated outsoles. The resulting similarity scores were sorted, and more than 91,000 of the mathematically most similar known non-match RACs with positional co-occurrence were visually assessed (in duplicate by two analysts) to determine their degree of observable resemblance. These empirical estimates of visual similarity were used to model resemblance as a Bernoulli distribution with binary outcomes (indistinguishable/distinguishable). Using a logistic regression, the conditional probability of sufficient resemblance, given a mathematical match score, or p(indistinguishability|score), was estimated and used to predict the likelihood of encountering indistinguishable features for the remaining less-similar 1.0 million RAC pairs in the dataset with the same geometric/shape categorization (linear, compact or variable) (1, 105, 943−91, 607=1, 014, 336). Part 1 of this effort reports the intersection of co-occurrence in spatial position and resemblance with results indicating that the median estimate of indistinguishability based on the upper 95% credible interval for estimation (or worst-case scenario) is 1 in 444,126 for linear, 1 in 291,111 for compact, and 1 in 880,774 for variable features. Part 2 of this effort will report random match probabilities for the same dataset.

Proteomic genotyping of fingermark donors with genetically variant peptides

Proteomic genotyping detects single amino acid polymorphisms to infer the genotype of corresponding non-synonymous SNPs. Like any DNA genotype, these inferences can be used to estimate random match probability. Fingermarks are a common source of biological evidence that is sample limited and a highly variable source of identifying DNA. Genetically variant peptides from fingermarks, that contain single amino acid polymorphisms, are an additional source of identifying genetic information. To discover these peptide biomarkers epidermal corneocytes from 9 subjects were isolated, processed, digested with trypsin and applied to mass spectrometry. The resulting proteomic and matching exome datasets were used to discover, characterize and validate 60 genetically variant peptides. An average of 28.8 ± 4.4 genetically variant peptides were detected from each subject resulting in a total of 264 SNP allele inferences with 260 true and 4 false positives, a false discovery rate of 1.5%. Random match probabilities were estimated using the genotype frequencies from the matching major populations in the 1000 Genomes Project. Estimates ranged up to a value of 1 in 1.7 × 108, with a median probability of 1 in 2.4 × 106. Furthermore, the proteomically-inferred genotypes are likely to be compatible with the STR-based random match probability estimates since the closest STR locus was 2.2 Mb from the nearest GVP-inferred SNP. This project represents a novel mode of genetic information that can be obtained from fingermarks and has the potential to complement other methods of human identification including analysis of ridge patterns or touch DNA.

Forensic stable isotope signatures: Comparing, geo‐locating, detecting linkage

AbstractStable isotope signatures or profiles of physical evidence such as illicit drugs, explosives or human tissue provide information on source, origin, even sample history not obtainable by traditionally applied analytical techniques of forensic chemistry. The discriminatory power, calculated as random match probability, of multivariate stable isotope signatures able to distinguish two cocaine samples from different regions in Colombia can range from one in tens of thousands to one in several million if based on the stable isotope abundances of carbon, nitrogen and hydrogen or carbon, nitrogen, hydrogen and oxygen, respectively. Stable isotope signatures of physical evidence have therefore at the very least great potential to provide invaluable forensic intelligence for intelligence led policing. They may even be of great evidentiary value, especially if corroborated by results from independent analytical techniques. This review aims to offer a glimpse into the fascinating world of forensic stable isotope analysis by discussing the various levels of information stable isotope signatures can provide. For reasons easily appreciated, only a select few instances of its application to criminal investigations have been reported in scientific journals thus far. The various applications of this technique presented in this review are therefore predominantly taken from peer‐reviewed work published in scientific books and journals.This article is categorized under: Forensic Biology > Interpretation of Biological Evidence Forensic Chemistry and Trace Evidence > Explosive Analysis Toxicology > Drug Analysis

Comparison of protein expression levels and proteomically-inferred genotypes using human hair from different body sites

The microanatomy of human hair differs as a function of the site of origin on the body. This was a major consideration when anatomical features of hair were used as a means of comparison and human identification. Recent advances have demonstrated that proteomics of the hair shaft can be used to develop profiles of protein abundance and genetically variant peptides, the latter in turn being used to infer genotypes of SNP alleles. Because the profile of proteins would be expected to change as hair anatomy changes, it is an open question if the profile of genetically variant peptides will also change. While some sample to sample variation is expected, a potential drawback of using genetically variant peptides to infer an individual genotype is that the proteomic profile might change as a function of body site origin as well as an individual’s genotype. The hypothesis in this study is that the profile of hair shaft genetically variant peptides depends more on an individual’s genotype than on the site of hair shaft origin. To test this an analysis of both protein expression levels and genetically variant peptides was conducted on 4 body sites (scalp, axillary, beard and pubic hair) from 5 individuals with 4 biological replicates. Levels of protein expression were estimated using label-free quantification on resulting proteomic mass spectrometry datasets. The same datasets were then also analyzed for the presence of genetically variant peptides. This study demonstrates that the protein profiles of hair shafts varied as a function of somatic origin. By contrast the profile of genetically variant peptides, and resulting inferred genotype of SNP alleles, were more dependent on the individual. In this study random match probabilities ranged up to 1 in 196. Individual identification based on genetically variant peptides therefore can be obtained from human hair without regard to the site of origin. If the site of hair shaft origin was legally relevant then microscopic analysis is still necessary. This study demonstrates the utility of proteomic analysis for extracting forensic information from hair shaft evidence.

Calculating the posterior odds from a single-match DNA database search

Forensic evidence is often quantified by statisticians in terms of a likelihood ratio. When the evidence consists of a DNA match, the likelihood ratio is equal to the reciprocal of the ‘random match probability’ (p). When p is small (e.g. 1/10 million), the likelihood ratio is large (e.g. 10 million to 1). However, when a single match is obtained by searching a database, the prior odds that the forensic DNA was deposited by the matcher can be extremely low, in which case the posterior odds can be low as well despite the high likelihood ratio. Unfortunately, prosecutors, judges and jurors are at risk of misinterpreting the likelihood ratio as the posterior odds, a pervasive reasoning error known as base-rate neglect. Here, we propose a solution to that problem, which consists of evaluating the prior odds based on a case-independent estimate of the size of the active criminal population derived from database search statistics. The posterior odds that the forensic DNA belongs to the unidentified single-matcher can then be calculated (avoiding base-rate neglect).

Development of a Protein‐based Human Identification Capability from a Single Hair

Shed human hair (lacking root nuclear DNA) frequently contributes important information to forensic investigations involving human identification. Detection of genetic variation observed in amino acid sequences of hair proteins provides a new suite of identity markers that augment microscopic hair analysis and mitochondrial DNA sequencing. In this study, a new method that completely dissolves single hairs using a combination of heat, ultrasonication, and surfactants was developed. Dissolved proteins were digested and genetically variant peptide (GVP) profiles were obtained for single hairs (25mm) via high-resolution nanoflow liquid chromatography-based mass spectrometry and a novel exome-driven bioinformatic approach. Overall, 6519 unique peptides were identified and a total of 57 GVPs were confirmed. Random match probabilities ranged between 2.6×10-2 and 6.0×10-9 . The new bioinformatic strategy and ability to analyze GVPs in forensically relevant samples sizes demonstrate applicability of this approach to distinguish individuals in forensic contexts.

A single nucleotide polymorphism panel for individual identification and ancestry assignment in Caucasians and four East and Southeast Asian populations using a machine learning classifier.

Single nucleotide polymorphism (SNP) profiling is an effective means of individual identification and ancestry inferences in forensic genetics. This study established a SNP panel for the simultaneous individual identification and ancestry assignment of Caucasian and four East and Southeast Asian populations. We analyzed 220 SNPs (125 autosomal, 17 X-chromosomal, 30 Y-chromosomal, and 48 mitochondrial SNPs) of the DNA samples from 563 unrelated individuals of five populations (89 Caucasian, 234 Taiwanese Han, 90 Filipino, 79 Indonesian and 71 Vietnamese) and 18 degraded DNA samples. Informativeness for assignment (In) was used to select ancestry informative SNPs (AISNPs). A machine learning classifier, support vector machine (SVM), was used for ancestry assignment. Of the 220 SNPs, 62 were individual identification SNPs (IISNPs) (51 autosomal and 11 X-chromosomal SNPs) and 191 were AISNPs (100 autosomal, 13 X-chromosomal, 30 Y-chromosomal, and 48 mitochondrial SNPs). The 51 autosomal IISNPs offered cumulative random match probabilities (cRMPs) ranging from 1.56 × 10-21 to 3.16 × 10-22 among these five populations. Using AISNPs with the SVM, the overall accuracy rate of ancestry inference achieved in the testing dataset between Caucasian, Taiwanese Han, and Filipino populations was 88.9%, whereas it was 70.0% between Caucasians and each of the four East and Southeast Asian populations. For the 18 degraded DNA samples with incomplete profiling, the accuracy rate of ancestry assignment was 94.4%. We have developed a 220-SNP panel for simultaneous individual identification and ethnic origin differentiation between Caucasian and the four East and Southeast Asian populations. This SNP panel may assist with DNA analysis of forensic casework.

Population genetics of 19 Y-STR loci in Yanbian Korean samples from China.

China harbors 56 ethnic groups, including Korean, with a population size of approximately 1.92 million at the 2010 census. Most of the Koreans live in Northeastern parts of China, including Jilin (59.64%), Heilongjiang (20.21%), and Liaoning (12.55%) provinces, and the rest are spread to other parts of China. Koreans across China share a common culture, which is similar to Korea. We have explored the genetic characteristics of 20 Y-chromosomal short tandem repeat (Y-STR) loci in 252 unrelated Chinese Korean male individuals from Jilin Province, using a Goldeneye 20Y amplification kit. Moreover, phylogenetic analysis was performed between the Korean population and other relevant populations based on the Y-STR haplotypes. We have found 237 different haplotypes among 252 unrelated individuals. The haplotype frequencies ranged from 0.0238 to 0.0040, while gene diversity ranged from 0.9666 (DYS385a/b) to 0.2260 (DYS391). The random match probability was 0.0048, the haplotype diversity was 0.9992 ± 0.0006 and discrimination capacity was 0.9405. Population comparison revealed that Korean populations are lining up together with other Korean populations from East Asia. Our results showed that the 20 Y-STR loci in the Yanbian Korean population are valuable for forensic application and human genetics. The Yanbian Koreans have lined up with other Korean population from China and Korea while showing significant differences from other East Asian populations.

An inter-laboratory evaluation of LA-ICP-MS analysis of glass and the use of a database for the interpretation of glass evidence

Ten laboratories conducting forensic glass analysis participated in three inter-laboratory exercises to evaluate the use of a standard method (ASTM 2927-16e1) for the analysis and comparison of glass evidence using LA-ICP-MS. This study was designed to evaluate the rate of misleading evidence (ROME) when blind glass samples were distributed to the participants and asked to compare the glass samples (K vs. Q) and report their findings as they would in a case. Three different databases were used as background populations to calculate likelihood ratios (LRs) and frequency of elemental profile. The first database was composed of 420 vehicle windshield samples and the analytical data and application of this database is reported here, for the first time. The second database was provided by the BKA laboratory in Germany representing 385 casework samples including an assortment of float glass, container glass, and specialty glasses. The third background database was a combination of both databases. In the first inter-laboratory exercise, the likelihood ratio (LR) calculations result in 34/36 (94.4%) correct associations and no false inclusions for all labs. LRs in the second and third inter-laboratory exercises result in all participating laboratories correctly associating glass samples originating from the same source (57 comparisons) and all laboratories correctly discriminating glass samples from different sources (167 comparisons). The random match probability of glass samples known to originate from different glass sources was found to be ∼0.1% and in agreement with previously reported values by other researchers.

Allele frequencies of mitochondrial DNA HVR III 514\u2013524 (CA)n dinucleotide repeats in the Urali Kuruman tribal population of South India

BackgroundTo evaluate the 514–524 (CA)n dinucleotide repeats/allele of the mtDNA hypervariable region III in the Urali Kuruman tribe of Southern India. Blood samples were randomly collected from 100 healthy unrelated individuals, and complete mtDNA control region was amplified and sequenced by the Sanger sequencing method.FindingsThe present study revealed the presence of nucleotide insertion and deletion of C and A (CA/AC) at position 514–524 in 86 samples. Insertion of 1AC (14%) and 2AC (20%) and deletion of 1CA (49%) and 2CA (3%) were detected. A statistical estimate for this population showed a genetic diversity of 0.6866 and random match probability of 0.3202, and the discrimination power calculated was 0.6798.ConclusionThis study will be beneficial for personal identification and in forensic investigation casework.

Mitochondrial DNA control region diversity in a population from Parana state-increasing the Brazilian forensic database.

The entire mitochondrial DNA (mtDNA) control region (nucleotide position 16024-576) sequences were obtained through Sanger sequencing method for 122 individuals from Parana state, South of Brazil. We observed a total of 108 different haplotypes of which 97 were unique and 11 were shared by more than one individual. The haplogroups were classified according to the updated mtDNA phylogeny, by EMMA (estimating mitochondrial haplogroups using a maximum likelihood approach). Our results revealed the predominance of Amerindian haplogroups with a frequency of 49.2% of the population sample, followed by European lineages with 38.5% and 12.3% of African lineages. Parana population sample set presented a high haplotype diversity (0.9976) and the random match probability was 0.0106. The phylogenetical findings and the diversity indices confirm the high genetic heterogeneity of this population and suggest a high informativeness of mtDNA analyses in forensic cases. The population data will contribute to increase the Brazilian mtDNA database for forensic purposes and it is available through EMPOP (European DNA Profiling Group mitochondrial DNA population database) under the accession number EMP00714.

Increasing the discrimination power of ancestry- and identity-informative SNP loci within the ForenSeq™ DNA Signature Prep Kit

The use of single nucleotide polymorphisms (SNPs) in forensic genetics has been limited to challenged samples with low template and/or degraded DNA. The recent introduction of massively parallel sequencing (MPS) technologies has expanded the potential applications of these markers and increased the discrimination power of well-established loci by considering variation in the flanking regions of target loci. The ForenSeq Signature Preparation Kit contains 165 SNP amplicons for ancestry- (aiSNPs), identity- (iiSNPs), and phenotype-inference (piSNPs). In this study, 714 individuals from four major populations (African American, AFA; East Asian, ASN; US Caucasian, CAU; and Southwest US Hispanic, HIS) previously reported by Churchill et al. [Forensic Sci Int Genet. 30 (2017) 81–92; DOI: https://doi.org/10.1016/j.fsigen.2017.06.004] were assessed using STRait Razor v2s to determine the level of diversity in the flanking regions of these amplicons. The results show that nearly 70% of loci showed some level of flanking region variation with 22 iiSNPs and 8 aiSNPs categorized as microhaplotypes in this study. The heterozygosities of these microhaplotypes approached, and in one instance surpassed, those of some core STR loci. Also, the impact of the flanking region on other forensic parameters (e.g., power of exclusion and power of discrimination) was examined. Sixteen of the 94 iiSNPs had an effective allele number greater than 2.00 across the four populations. To assess what effect the flanking region information had on the ancestry inference, genotype probabilities and likelihood ratios were determined. Additionally, concordance with the ForenSeq UAS and Nextera Rapid Capture was evaluated, and patterns of heterozygote imbalance were identified. Pairwise comparison of the iiSNP diplotypes determined the probability of detecting a mixture (i.e., observing ≥ 3 haplotypes) using these loci alone was 0.9952. The improvement in random match probabilities for the full regions over the target iiSNPs was found to be significant. When combining the iiSNPs with the autosomal STRs, the combined match probabilities ranged from 6.40 × 10−73 (ASN) to 1.02 × 10-79 (AFA).

Protein-based forensic identification using genetically variant peptides in human bone

Bone tissue contains organic material that is useful for forensic investigations and may contain preserved endogenous protein that can persist in the environment for extended periods of time over a range of conditions. Single amino acid polymorphisms in these proteins reflect genetic information since they result from non-synonymous single nucleotide polymorphisms (SNPs) in DNA. Detection of genetically variant peptides (GVPs) — those peptides that contain amino acid polymorphisms — in digests of bone proteins allows for the corresponding SNP alleles to be inferred. Resulting genetic profiles can be used to calculate statistical measures of association between a bone sample and an individual. In this study proteomic analysis on rib cortical bone samples from 10 recently deceased individuals demonstrates this concept. A straight-forward acidic demineralization protocol yielded proteins that were digested with trypsin. Tryptic digests were analyzed by liquid chromatography mass spectrometry. A total of 1736 different proteins were identified across all resulting datasets. On average, individual samples contained 454±121 (x¯±σ) proteins. Thirty-five genetically variant peptides were identified from 15 observed proteins. Overall, 134 SNP inferences were made based on proteomically detected GVPs, which were confirmed by sequencing of subject DNA. Inferred individual SNP genetic profiles ranged in random match probability (RMP) from 1/6 to 1/42,472 when calculated with European population frequencies in the 1000 Genomes Project, Phase 3. Similarly, RMPs based on African population frequencies were calculated for each SNP genetic profile and likelihood ratios (LR) were obtained by dividing each European RMP by the corresponding African RMP. Resulting LR values ranged from 1.4 to 825 with a median value of 16. GVP markers offer a basis for the identification of compromised skeletal remains independent of the presence of DNA template.

DNA typing of birch: Development of a forensic STR system for Betula pendula and Betula pubescens

Although botanical trace evidence is often encountered in case investigations, the utilization of such traces in forensic investigations is still limited. Development of a forensic STR system for the two species of Betula (birch) indigenous to and abundant in North West Europe is a step in enhancing the applicability of traces from these species. We describe six microsatellite markers developed for birch species in detail, including repeat structure, and we propose a nomenclature for the encountered alleles. To assess the population characteristics, the genetic composition of wild, planted and intermediate populations of Betula pendula (a diploid species) and Betula pubescens (a tetraploid species) were investigated. The genetic differences between these two species were larger than the differences between populations of one species, even when both species co-occurred at one location. Therefore allele frequencies were estimated for both species separately. General, conservative random match probabilities were estimated for wild trees based on these allele frequencies (5∙10−6 for the diploid B. pendula and 1∙10−13 for the tetraploid B. pubescens), illustrating the potential relevance if trace evidence secured from a suspect is found to match a birch tree growing on or near a crime scene. Apart from wild trees, planted Betula trees also occur that may not originate from seeds, but may have been propagated through cloning. Based on the studied Betula trees, the random match probability of a potentially planted profile might be as high as 1.4∙10−2.

The redesigned Forensic Research/Reference on Genetics-knowledge base, FROG-kb

The Forensic Resource/Reference on Genetics-knowledge base (FROG-kb) web site <https://frog.med.yale.edu/FrogKB/> was introduced in 2011 and in the five years since the previous publication ongoing research into how the database can better serve forensics has resulted in extensive redesign of the database interface and functionality. Originally designed as a prototype to support forensic use of single nucleotide polymorphisms (SNPs), FROG-kb provides a freely accessible web interface that facilitates forensic practice and can be useful for teaching and research. Based on knowledge gained through its use, the web interface has been redesigned for easier navigation through the multiple components. The site also has functional enhancements, extensive new documentation, and new reference panels of SNPs with new curated data. FROG-kb focuses on single nucleotide polymorphisms (SNPs) and provides reference population data for several published panels of individual identification SNPs (IISNPs) and several published panels of ancestry inference SNPs (AISNPs). For each of the various marker panels with reference population data, FROG-kb calculates random match probabilities (RMP) and relative likelihoods of ancestry for a user-entered genotype profile (either completely or partially specified). Example genotype profiles are available and the User’s Manual presents interpretation guidelines for the calculations. The extensive documentation along with ongoing updates makes FROG-kb a comprehensive tool in facilitating use of SNPs in forensic practice and education. An overview of the new FROG-kb with examples and material explaining the results of its use are presented here.

Microhaplotypes for ancestry prediction

Microhaplotypes (MHs) are loci of two or more SNPs within a short distance from each other (<300 nucleotides) with three or more allelic combinations. Massively parallel sequencing (MPS) is clonal sequencing of individual strands, thus it can distinguish the parental haplotypes at a locus. MH alleles within a locus all have the same size, do not generate stutter fragments, and have lower mutation rates than STRs. The goal of this project was to determine whether MHs could provide biogeographic ancestry prediction.A total of 278 samples including 76 African-Americans (AAs), 110 European-Americans (EAs) and 92 South West Hispanics (SWHISPs) were selected and genotyped using a 74-plex assay on the Ion Chef™ and Ion S5™ MPS platform. Results were used to generate allele frequencies for the three populations. A set of test samples (28) was genotyped and used to calculate the random match probability (RMP) in the three populations. Additionally, PHASE inferred allele frequencies from 24 populations obtained from ALFRED were used to calculate the RMP of the test samples in each population. A mixture study was also performed to evaluate the detection limit for the minor contributor of the MH 74-plex.Among the populations studied, the RMP averaged remarkably higher in each individual’s self-identified population of “origin”. For example, AAs had the highest RMP in African and African-American populations. In the mixture study results showed that alleles from the minor contributor were detectable at an 80:1 major/minor ratio when the input DNA was 10ng and 40:1 when the input amount was 1ng with a RMP equal to or greater than a typical 15 loci STR profile demonstrating that MHs can be an effective tool for ancestry prediction and mixture analysis.

Genetic diversity of Mexican-Mestizo populations using 114 INDEL polymorphisms

We analyzed 154 unrelated individuals from four Mexican-Mestizo (admixed) populations with 114 INDEL loci; 68 of them have been proposed for forensic use and 46 constitute Ancestry informative markers (AIM-INDELs). Allele frequencies and genetic diversity were calculated for all these loci. The Hardy-Weinberg equilibrium was demonstrated for 113 loci, excepting the 360 locus (AIM-INDEL). Linkage disequilibrium (LD) test only showed departure for the HLD45/HLD64 combination among the 68 INDEL loci. Random match probability (RMP), power of discrimination (PD), and power of exclusion (PE) for the 68 INDELs are reported. The combined PD and PE were similar to those from STR systems: >0.999999999999999 and 0.999996089797308, respectively; whereas the RMP was <5.54×10−22. AMOVA and structure analyses showed moderated interpopulation differentiation, which support the establishment of a national DNA database for forensic casework interpretation in Mexico when using these 68 INDELs. The ancestral proportions assessed from 46 AIM-INDELs displayed differences mainly for the Native American (0.462–0.702) and European (0.487–0.254) ancestries, while the African was relatively homogeneous (0.028–0.052).

Evaluation of InnoTyper® 21 in a sample of Rio de Janeiro population as an alternative forensic panel.

The use of bi-allelic markers such as retrotransposable element insertion polymorphisms or Innuls (for insertion/null) can overcome some limitations of short tandem repeat (STR) loci in typing forensic biological evidence. This study investigated the efficiency of the InnoTyper® 21 Innul markers in an urban admixed population sample in Rio de Janeiro (n=40) and one highly compromised sample collected as evidence by the Rio de Janeiro police. No significant departures from Hardy-Weinberg equilibrium were detected after the Bonferroni correction (α'≈0.05/20, p<0.0025), and no significant linkage disequilibrium was observed between markers. Assuming loci independence, the cumulative random match probability (RMP) was 2.3×10-8. A lower mean Fis value was obtained for this sample population compared with those of three North American populations (African-American, Southwest Hispanic, US Caucasian). Principal component analysis with the three North American populations and one from 21 East Asian population showed that African Americans segregated as an independent group while US Caucasian, Southwest Hispanic, East Asian, and Rio de Janeiro populations are in a single large heterogeneous group. Also, a full Innuls profile was produced from an evidence sample, despite the DNA being highly degraded. In conclusion, this system is a useful complement to standard STR kits.

Genetic perspective of uniparental mitochondrial DNA landscape on the Punjabi population, Pakistan

To investigate the uniparental genetic structure of the Punjabi population from mtDNA aspect and to set up an appropriate mtDNA forensic database, we studied maternally unrelated Punjabi (N = 100) subjects from two caste groups (i.e. Arain and Gujar) belonging to territory of Punjab. The complete control region was elucidated by Sanger sequencing and the subsequent 58 different haplotypes were designated into appropriate haplogroups according to the most recently updated mtDNA phylogeny. We found a homogenous dispersal of Eurasian haplogroup uniformity among the Punjab Province and exhibited a strong connotation with the European populations. Punjabi castes are primarily a composite of substantial South Asian, East Asian and West Eurasian lineages. Moreover, for the first time we have defined the newly sub-haplogroup M52b1 characterized by 16223 T, 16275 G and 16438 A in Gujar caste. The vast array of mtDNA variants displayed in this study suggested that the haplogroup composition radiates signals of extensive genetic conglomeration, population admixture and demographic expansion that was equipped with diverse origin, whereas matrilineal gene pool was phylogeographically homogenous across the Punjab. This context was further fully acquainted with the facts supported by PCA scatterplot that Punjabi population clustered with South Asian populations. Finally, the high power of discrimination (0.8819) and low random match probability (0.0085%) proposed a worthy contribution of mtDNA control region dataset as a forensic database that considered a gold standard of today to get deeper insight into the genetic ancestry of contemporary matrilineal phylogeny.

A Fully Automatic Method for Comparing Cartridge Case Images,

When a gun is fired, it leaves marks on cartridge cases that are thought to be unique to the gun. In current practice, firearms examiners inspect cartridge cases for "sufficient agreement," in which case they conclude that they come from the same gun, testifying in courts as such. A 2016 President's Council of Advisors on Science and Technology report questioned the scientific validity of such analysis (President's Committee of Advisors on Science and Technology, Washington, DC, Executive Office of the President). One recommendation was to convert firearms analysis to an objective method. We propose a fully automated, open-source method for comparing breechface marks on cartridge cases using 2D optical images. We improve on existing methodology by automating the selection of marks, and removing the effects of circular symmetry. We propose an empirical computation of a "random match probability" given a known database, which can be used to quantify the weight of evidence. We demonstrate an improvement in accuracy on images from controlled test fires.