Forensic Identification Research Articles

Isotopic heterogeneity in U.S. Urban water supply systems reflects climatic, environmental, and sociodemographic factors: Implications for forensic identification

The forensic application of stable oxygen isotope data from human tissues depends on naturally occurring isotopic variation in drinking water across geographic areas. One factor which complicates interpretation of forensic data is local variability: if a wide range of drinking water values is in a small geographic region it may be difficult to identify or rule out that region as a location of origin. We examine data from community collection programs documenting tap water isotope variation within 30 cities\developed areas throughout the United States. Isotopic variation within individual developed areas ranged widely, from essentially nil to greater than 9‰ (δ18O interdecile range). Many (14/30) of the study areas exhibited multi-modal isotope distributions, even in cases where the isotopic range was very small (e.g., <2.0‰), suggesting that the use of multiple, isotopically different sources was common. Most variation was attributed to differences in the source-region altitude or degree of evaporation for different water sources, and we observe limited variation in areas where contrasts in these variables are small. Variation tended to be largest in cities across the western USA. We explored correlations between the magnitude of local isotopic variation and climatic, environmental, and socioeconomic variables. We found that higher levels of variation occurred at sites where local water resources were likely to be more isotopically heterogeneous and in lower supply, consistent with the development of supply systems in these areas that access diverse and isotopically heterogeneous water resources. We also found that variation was positively correlated with larger developed areas, suggesting that pressures related to city growth may affect the degree to which infrastructure tapping diverse water resources is developed. Collectively, our results suggest that the influence of local tap water isotope heterogeneity on the precision of forensic geolocation is systematic and somewhat predictable, information to be factored into future applications.

Synthesis and application of Ho³⁺ doped BaGd₂ZnO₅ nanophosphors for enhanced latent fingerprint development and poroscopy

In this study, Ho³⁺-doped BaGd₂ZnO₅ (1–11 mol%) nanophosphors (BGZO:Ho3+ NPs) were synthesized through combustion synthesis, utilizing Spirulina leaf extract as a natural green fuel. Luminescence studies revealed that the BGZO:Ho³⁺ phosphors exhibit a strong green emission primarily resulting from the 5S2→5I8 transition of Ho³⁺ ions. The optimal doping concentration was found to be 7 mol % Ho³⁺, which yielded the highest luminescence efficiency. Furthermore, the CIE chromaticity coordinates for BGZO:7Ho³⁺ were accurately determined to be (0.2595, 0.7290), with a color purity (CP) of 99.98 %. These results indicate the potential of this material for producing high-quality green emissions suitable for solid-state lighting and display applications. Optimized BGZO:Ho3+ NPs were utilized for latent fingerprints (LFPs) development via the powder dusting method. Under 365 nm UV light, the NPs effectively revealed Level I-III fingerprints (FPs) details, including ridge patterns, minutiae, and sweat pore features, on various substrates such as glass, plastic, and metal. The high luminescence of BGZO:Ho3+ NPs under UV illumination offers a sensitive and non-destructive method for enhancing FPs visibility, making it a promising tool for forensic applications. In addition, this study focuses on FPs poroscopy, examining the detailed pore structure of LFPs for forensic identification. Using advanced imaging techniques, we analyzed sweat pore distribution, size, and shape across various substrates and conditions. A detailed poroscopic analysis of LFPs, focusing on key parameters such as pore interspacing (165–332 μm), pore size (4140–9956 μm2), shapes (elliptical, rhomboid, triangular, square and rectangular) and pore angle (167°–179°). Further, a mathematical model was developed using Python-based software to enable precise and accurate analysis of FPs, enhancing clarity and identification accuracy, supporting the uniqueness of FPs beyond ridge patterns. The results demonstrate the potential of poroscopy for enhancing FPs analysis by offering an additional layer of precise biometric data.

Knowledge and ignorance in forensic identification: the origins of a contested human rights fact

ABSTRACT In 2006, DNA testing revealed that the Chilean Medical Legal Service had misidentified at least half of the 96 human rights victims whose remains had been exhumed in 1991 from a lot in the Santiago General Cemetery known as Patio 29. Years earlier the government had returned those remains to the victims' families. This examination of the history of that forensic misidentification uncovers the role played by the shifting relations of knowledge and ignorance in establishing the legal facts of those identities. Building on the growing literature in agnotology, the article demonstrates the ways in which the context of dictatorship created varied and overlapping forms of ignorance that continued to shape the outcome of the forensic work even after Chile returned to democracy. By detailing different examples of ignorance production by the state, a human rights organization, and a university department under military surveillance, the article illuminates the diverse ways that the civil–military dictatorship worked against knowledge production in the domains of science and human rights.

Effects of prescreening for likelihood ratio approaches in the forensic identification of source problems

Source prescreening is a methodology where forensic examiners select samples that are similar to given trace evidence to represent the background population. This background evidence helps assign a value of evidence using a likelihood ratio or Bayes factor. A potential benefit of prescreening is a mitigation of effects from subpopulation structures within the alternative source population by isolating the relevant subpopulation. This paper examines the impact of prescreening before assigning evidence value. Extensive simulations with synthetic and real data, including trace element and fingerprint score examples, were conducted. The findings indicate that when the subpopulation structure is known, prescreening can provide an accurate evidence value in cases of subpopulation structures. The study suggests that prescreening can be beneficial, but the prescreening method and level should be transparently reported alongside the evidence value.

IDENTIFEYE: Sketch-Based Facial Analysis in Forensics

Traditional forensic methods, like hand-drawn sketches, often fall short in quickly identifying suspects, making the process both slow and resource-intensive. This paper introduces an innovative application designed to streamline this task. Through a simple drag-and-drop interface, users can upload sketches and match them with entries in police databases, significantly boosting the speed and accuracy of suspect recognition. By integrating deep learning and cloud technology, this tool builds on existing algorithms to deliver higher precision and ease of use. Earlier methods have had trouble aligning sketches with photographs, especially when orientations differ. Our application overcomes these issues, merging the art of sketching with modern technology to enhance forensic work. Testing reveals promising accuracy, though ongoing improvements are needed to fully meet the demands of law enforcement. This research aims to offer a real-world solution, tackling past limitations and making suspect identification faster and more efficient for investigators. Keywords: Forensic identification, Suspect sketching, Deep learning, Recognition software, Law enforcement tools, Cloud technology.

A nationwide Swedish retrospective study on poisoning deaths between the years 2000 and 2022.

Approximately 1% of Sweden's 90 000 annual deaths were reported caused by poisoning. In this study, we aim to describe this poisoning population's characteristics, autopsy frequency and results of toxicology testing. A national cohort study based on Swedish national registers. All deceased subjects older than 18 years with poisoning as the cause of death registered between 1 January 2000 and 31 December 2021 were included. Causes of death according to primary ICD-10 code were analysed along with the substances found in forensic chemistry testing. There were 27 057 poisonous deaths during the study periods 2 018 495 adult deaths. Subjects deceased due to poisoning had a median age of 53 years, and 18 838 (70%) were men. A private home was the most reported location of death (52%). In total, 23 260 (87%) did undergo some sort post-mortem examination. Drugs (synthetic narcotics, opioids, heroin) caused 12 448 (46%) deaths, and alcohols explained 9056 cases (33%). Positive toxicological tests were found in 22 550 (83%) of the subjects. The most common separate substances were ethanol, zopiclone and nordazepam. Poisoning caused 1.3% of Swedish deaths. Men in their 50s were the most common victims, and their deaths were often cause by synthetic narcotics, other opioids or alcohol. The autopsy frequency was lower than expected for poisonous deaths.

Portable near-infrared detection to replace color tests in an analytical scheme for forensic drug identification

In the ever-changing drug market the popularity and availability of substances is dynamic. In the Netherlands, ketamine and various cathinones have recently seen increased prevalence. It is crucial for law enforcement to quickly obtain an initial indication of the identity of a substance. This first test also serves as quality control for subsequent confirmation with GC–MS analysis. Traditionally, color tests have been used for these purposes. While these tests are quick and inexpensive, they have the disadvantage of reacting only to a few traditional drugs. Suitable color tests are not available for many new psychoactive substances (NPS). Near-infrared (NIR) spectroscopy is a rapid technique that provides a characteristic spectrum for organic compounds. This technique is more versatile than color tests and can adapt more quickly to market changes by incorporating reference spectra into the library. This study demonstrates the feasibility of obtaining a good quality NIR spectrum from a 20 mg sub-sample in a test tube. This was achieved by scanning the test tube through the glass bottom. In the routine analytical scheme, these test tubes were subsequently batchwise analyzed by GC–MS. From the NIR spectra, 84 % true positive and 100 % true negative results were achieved on 516 casework samples, including identification of substances without available color tests like ketamine. Missed false negatives primarily involved new substances absent from the library, emphasizing the need for continuous library updates. NIR’s adaptability to market changes is crucial, allowing the inclusion of new substances as they emerge. This method enhances law enforcement’s ability to make informed decisions, aiding in the indictment process.

Morphometric Assessment of the Piriform Aperture and Its Clinical and Forensic Applications

Abstract Background: The piriform aperture (PA) is a midface structure that forms the anterior skeletal boundary of the nose. It is highly variant due to its physiological adaptations to the climate. Its variations are useful in forensic identification and reconstructive surgeries of the face. This study aimed at determining the PA’s dimensions and their accuracy in sex determination. Materials and Methods: The PA’s dimensions were retrospectively examined using 336 (199 males and 137 females) adult cranial computed tomography images in the database of the radiology unit of a university teaching hospital in Delta State, Nigeria, following institutional authorization. The aperture’s index was calculated as a ratio of height to width. The data were analyzed using Statistical Package for the Social Sciences Version 23. The sexual dimorphism in the parameters was assessed using an independent t-test. Association among the continuous variables was analyzed by Pearson’s correlation test. P = 0.05 was considered statistically significant. The percentage accuracy for correct sex prediction was assessed using the discriminant function analysis. Results: A significant relationship between dimensions with sex was observed (P < 0.05). The width of the aperture was the best sex-discriminating parameter (70.2%). The overall accuracy for sex discrimination using the aperture’s dimensions was 75.0%. Conclusion: This study provides the standard ranges for the PA’s width and height, valuable for surgical planning. These dimensions were sexually dimorphic and demonstrated an acceptable overall accuracy of correct sex allocation (75%). Consequently, this aperture may be utilized as a supplementary tool in conjunction with other methods for sex determination within studied population.

Characterisation of identity-informative genetic markers in the Australian population with European ancestry

Identity-informative single nucleotide polymorphisms (iiSNPs) are valuable genetic markers for human identification and kinship testing in forensic casework, especially when the quality and quantity of DNA evidence is not suitable for routine short tandem repeat (STR) profiling. This study analysed 105 buccal samples representing the Australian population with European ancestry in order to assign allele frequencies and conduct population genetic analyses for 94 iiSNPs and 20 STRs. The markers were assessed by calculating relevant forensic statistics and testing for deviations from Hardy-Weinberg and linkage equilibrium. No linkage of statistical significance was observed between any of the pair-wise combinations of the combined 114 identity-informative markers and only one STR exhibited deviation from Hardy-Weinberg equilibrium (D8S1179). The probability of matching genotypes being observed within this population was of the order of 10−23 for STRs, 10−38 for iiSNPs and 10−60 for the combined identity-informative marker panel, improving the ability to discriminate between individuals when calculating likelihood ratios in direct or indirect matching scenarios. Further, the addition of iiSNPs will facilitate identifications when suboptimal STR profiles are recovered from compromised or challenging samples and aid comparisons to genetic relatives for familial or kinship testing.

Data-driven fingerprint nanoelectromechanical mass spectrometry

Fingerprint analysis is a ubiquitous tool for pattern recognition with applications spanning from geolocation and DNA analysis to facial recognition and forensic identification. Central to its utility is the ability to provide accurate identification without an a priori mathematical model for the pattern. We report a data-driven fingerprint approach for nanoelectromechanical systems mass spectrometry that enables mass measurements of particles and molecules using complex, uncharacterized nanoelectromechanical devices of arbitrary specification. Nanoelectromechanical systems mass spectrometry is based on the frequency shifts of the nanoelectromechanical device vibrational modes that are induced by analyte adsorption. The sequence of frequency shifts constitutes a fingerprint of this adsorption, which is directly amenable to pattern matching. Two current requirements of nanoelectromechanical-based mass spectrometry are: (1) a priori knowledge or measurement of the device mode-shapes, and (2) a mode-shape-based model that connects the induced modal frequency shifts to mass adsorption. This may not be possible for advanced nanoelectromechanical devices with three-dimensional mode-shapes and nanometer-sized features. The advance reported here eliminates this impediment, thereby allowing device designs of arbitrary specification and size to be employed. This enables the use of advanced nanoelectromechanical devices with complex vibrational modes, which offer unprecedented prospects for attaining the ultimate detection limits of nanoelectromechanical mass spectrometry.

Inferring ancestry with the hierarchical soft clustering approach tangleGen.

Understanding the genetic ancestry of populations is central to numerous scientific and societal fields. It contributes to a better understanding of human evolutionary history, advances personalized medicine, aids in forensic identification, and allows individuals to connect to their genealogical roots. Existing methods, such as ADMIXTURE, have significantly improved our ability to infer ancestries. However, these methods typically work with a fixed number of independent ancestral populations. As a result, they provide insight into genetic admixture, but do not include a hierarchical interpretation. In particular, the intricate ancestral population structures remain difficult to unravel. Alternative methods with a consistent inheritance structure, such as hierarchical clustering, may offer benefits in terms of interpreting the inferred ancestries. Here, we present tangleGen, a soft clustering tool that transfers the hierarchical machine learning framework Tangles, which leverages graph theoretical concepts, to the field of population genetics. The hierarchical perspective of tangleGen on the composition and structure of populations improves the interpretability of the inferred ancestral relationships. Moreover, tangleGen adds a new layer of explainability, as it allows identifying the SNPs that are responsible for the clustering structure. We demonstrate the capabilities and benefits of tangleGen for the inference of ancestral relationships, using both simulated data and data from the 1000 Genomes Project.

Comprehensive Study of Various Chemical Samples in Forensic Toxicology: Focus on Urine Sample

Toxicology deals with the measurement and analysis of toxins. It is itself a vast branch of science, though it has several branches and one of these is forensic toxicology. Forensic toxicology is a branch of toxicology that lines up with other disciplines, namely clinical chemistry, postmortem forensic toxicology, human performance toxicology and forensic drug testing, providing medical jurisprudence of adverse effects such as drug abuse, poisoning and death. The key role of forensic toxicology is to identify and analyse the toxin compounds found during adverse events. This review paper aims to draw an idea about the toxin, in the collected biological chemical samples such as urine samples and their effects on their day-to-day life.

Development of a forensic DNA research grade test material.

Advancements in forensic DNA typing technology and methods have increased sensitivity and, while beneficial, carry the weight of more challenging profile interpretation. In response, the forensic DNA community has often requested more complex reference materials to address commonly encountered measurement and interpretation issues such as complex DNA mixtures, DNA degradation, and PCR inhibition. The National Institute of Standards and Technology (NIST) released Research Grade Test Material 10235: Forensic DNA Typing Resource Samples to support the forensic DNA community. Components include three single source samples, two degraded samples, and three mixture samples. As part of the Research Grade Test Material (RGTM) process, automated methods for bottling, alternative sample tube types, and the addition of carrier RNA for stabilizing low-quantity samples were investigated. Both internal and external testing demonstrate the stability of the material over time at 4°C through qPCR testing. In the development of a data portal, users have been allowed to anonymously upload results and compare their data with NIST and others. This report describes the preparation and stability of this material.

Developmental and validation of a novel small and high-efficient panel of microhaplotypes for forensic genetics by the next generation sequencing

BackgroundIn the domain of forensic science, the application of kinship identification and mixture deconvolution techniques are of critical importance, providing robust scientific evidence for the resolution of complex cases. Microhaplotypes, as the emerging class of genetic markers, have been widely studied in forensics due to their high polymorphisms and excellent stability.Results and discussionIn this research, a novel and high-efficient panel integrating 33 microhaplotype loci along with a sex-determining locus was developed by the next generation sequencing technology. In addition, we also assessed its forensic utility and delved into its capacity for kinship analysis and mixture deconvolution. The average effective number of alleles (Ae) of the 33 microhaplotype loci in the Guizhou Han population was 6.06, and the Ae values of 30 loci were greater than 5. The cumulative power of discrimination and cumulative power of exclusion values of the novel panel in the Guizhou Han population were 1-5.6 × 10− 43 and 1-1.6 × 10− 15, respectively. In the simulated kinship analysis, the panel could effectively distinguish between parent-child, full-sibling, half-sibling, grandfather-grandson, aunt-nephew and unrelated individuals, but uncertainty rates clearly increased when distinguishing between first cousins and unrelated individuals. For the mixtures, the novel panel had demonstrated excellent performance in estimating the number of contributors of mixtures with 1 to 5 contributors in combination with the machine learning methods.ConclusionsIn summary, we have developed a small and high-efficient panel for forensic genetics, which could provide novel insights into forensic complex kinships testing and mixture deconvolution.

Creating Solvability With Real-Time Crime Centers (RTCCs): Impacts on Homicide and Shooting Investigations

Amidst recent increases in homicides and shootings in the United States, clearances rates for homicides have declined and nonfatal shooting cases remain notoriously difficult to solve. Considerable research indicates that the outcomes of homicide and shooting investigations are likely influenced by a range of factors, including inherited case characteristics, investigative actions, forensic testing, and agency resources. Recent advancements in technologies available to law enforcement may help fill persistent gaps in solvability, but research remains limited on their effectiveness. RTCCs integrate a variety of technological innovations and software programs to rapidly receive and distribute information to support police operations, and they harness the strong potential to powerfully impact investigative outcomes and offer an additional pathway through which police agencies can increase case clearance. The current study explores the impact of strategic efforts in the Hartford Police Department (HPD) to increase investigative effectiveness through RTCC processes and technologies. Our findings indicate that RTCC activities significantly increase the likelihood that a case is solved, and this effect is primarily due to RTCC analysts’ ability to locate and analyze video associated with the case. When associated video was located, cases were 442% more likely to be solved when controlling for other covariates. The HPD’s RTCC operations, institutionalized technology, and organizational culture also play a crucial role, with a commitment to technology and information-sharing enhancing investigative capabilities. This study emphasizes the effectiveness of real-time crime centers in locating digital evidence, facilitating rapid information dissemination, and fostering agencywide collaboration, ultimately improving investigative outcomes.

Design of a Multi-Vision System for a Three-Dimensional Mug Shot Model to Improve Forensic Facial Identification

Design of a Multi-Vision System for a Three-Dimensional Mug Shot Model to Improve Forensic Facial Identification

A new insight of blood vs. buccal DNA methylation in the forensic identification of monozygotic triplets

The case of the monozygotic (MZ) twin as a suspect demonstrates a practical problem in forensic casework. As the MZ twins are genetically identical, they share the same short tandem repeat (STR) profile. Many studies showed that older MZ twins have significant differences in overall content and genomic distribution of methylation between them. However, studies addressing the investigation of epigenetic MZ triplet differentiation in various forensic reference materials are lacking. Here, one triplet set of Egyptian MZ twins was used as an analog to a forensic case. The genome-wide methylation analysis was performed via the new Human Methylation EPIC BeadChip array. Following normalization methods, potential differentially methylated positions (DMPs) were discovered. This resulted in the detection of 24 potential DMPs in reference-type blood DNA and 11 potential DMPs in reference-type buccal DNA. Then, the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were performed to show the associated biological functions. Our findings revealed that the 35 potential DMPs were enriched in 283 significant GO terms. These terms are mainly enriched in the immune system. Overall, this study demonstrates the general feasibility of epigenetic MZ triplet differentiation in the forensic context and highlights that some potential DMPs identified in blood DNA were not informative in buccal DNA. This is due to various reasons, including the tissue specificity of DNA methylation.

Forensic identification of abo blood grouping from teeth under different conditions using absorption elution method

Forensic identification of abo blood grouping from teeth under different conditions using absorption elution method

Cold Temperatures and Weather Processes on Human Bone

Amongst research on forensic skeletal material found in a variety of environmental conditions, cold climate contexts and the effects of various associated weather processes are very under-researched. This paper will examine existing sources on the effects of cold and freezing weather conditions on forensic anthropology analyses. It will review the various taphonomic processes that occur from sub-zero temperatures, like snow, ice, and freeze-thaw cycles on bone, as well as the associated challenges that could arise in identifying important features and analyzing skeletal remains when found in these conditions. Finally, this paper will discuss the research gap of the effects of cold weather climates on bone and will explore some much-needed new and expanding avenues of research on this topic, which could aid forensic identifications and analyses on human remains in cold climates.

Forensic facial identification – reconstruction of facial geometry and shape from dental dimensions

Human identification has always remained as a main task of forensic anthropology and forensic science for various purposes. The purpose of human identification may vary from legal identity to disaster victim identification, from criminal identity to unidentified deceased identification. The condition, such as putrefaction, charring and mutilation of corpse always become an obstacle during the process of identification. Due to surviving nature of teeth, they may serve as evidence for identification in highly decomposed conditions. Therefore, a cross-sectional study was conducted on 207 participants (93 males and 114 females) in the age range of 21 to 45 years with the aim of two-dimensional facial reconstruction. Dental casts, anthropometric facial measurements and facial photographs were obtained from the participants. Dental measurements were taken on the cast in the laboratory. Statistical analysis revealed a weak but statistically significant correlation between the dental and facial parameters. The geometrical faces and the shapes were reconstructed based on the dental dimensions. The reconstructed facial geometry and shapes were very similar to the true facial geometry and facial shapes of the individual. By improving identification of disaster victims and unidentified deceased, the results of the study can have considerable implications in forensic and medico-legal case-works.