Forensic Casework Research Articles

Artificial Intelligence and Identification of the Deceased: a Narrative Review With Implications in Forensic Science.

Identification of the dead is of utmost importance in mass disasters, war crimes, and forensic examinations. The biological profile, established by a forensic anthropologist is one the necessary steps involved in the identification of the dead. Several parameters can be estimated such as sex, age, stature, biogeographical affinity, and DNA profile of the unknown person. It is crucial to estimate these parameters of identification which may narrow down the investigation process. On the other hand, Artificial Intelligence (AI) in the modern world is showing magical uses in different fields. This communication aims to highlight the uses of AI tools for predicting parameters such as sex, age, stature, biogeographical affinity, and DNA profile of unknown persons with more accuracy and in less time. A literature search was conducted using databases PubMed, Scopus, Web of Science, and ScienceDirect for analyzing the use of artificial intelligence, machine learning, and deep learning algorithms for establishing the biological profile in disaster victim identification (DVI) and forensic casework. Moreover, this research foresees a paradigm shift in investigative techniques as technology advances, highlighting the convergence of AI and anthropological ideas for an improved understanding of the biological profiles of unknown deceased individuals.

Enhancing trace DNA profile recovery in forensic casework using the amplicon RX post-PCR clean-up kit

This study evaluated the effectiveness of the amplicon RX post-PCR clean-up kit in enhancing trace DNA profile recovery from forensic casework samples amplified using the GlobalFiler PCR amplification kit. The impact of post-PCR clean-up on allele recovery and signal intensity was assessed in both trace casework samples and control samples across a range of DNA concentrations. The results showed that the amplicon RX method significantly improved allele recovery compared to the 29-cycle protocol (p = 8.30 × 10−12) and achieved slightly better results than the 30-cycle protocol (p = 0.019). Additionally, the Amplicon RX method demonstrated a significant increase in signal intensity (p = 2.70 × 10−4), reflecting improved sensitivity in detecting trace DNA profiles compared to the 30-cycle protocol. In the evaluation of control samples, the amplicon RX method consistently outperformed both the 29- and 30-cycle protocols, especially at lower DNA concentrations (D3: 0.001 ng/µL). While the performance of all methods declined at the lowest concentration (D4: 0.0001 ng/µL), the Amplicon RX method still demonstrated superior allele recovery (p = 0.014 compared to 29 cycles; p = 0.011 compared to 30 cycles). Therefore, the Amplicon RX method should be widely adopted in forensic laboratories to enhance the analysis of extremely low-template and compromised samples. These findings highlight the potential of the amplicon RX post-PCR clean-up kit to improve trace DNA analysis in forensic casework. Further research is recommended to validate these results and explore its broader application in forensic DNA analysis, particularly in complex DNA mixtures and extremely low-template samples.

Nanoparticle-assisted PCR: fundamentals, mechanisms, and forensic implications.

Polymerase Chain Reaction (PCR) has transformed forensic DNA analysis butis still limited when dealing with compromised trace or inhibitor-containing samples. Nanotechnology has been integrated into nanoPCR (nanoparticle-assisted PCR) to overcome these obstacles. Nanomaterials improve PCR sensitivity, selectivity, and efficiency. Examples of these materials are semiconductor quantum dots and metal nanoparticles. They enhance DNA binding to primers, stabilize enzymes, and function as effective heat conductors, making accurate amplification possible even with tainted samples. The developments in nanoPCR have potential uses in forensics, as they allow for the more sensitive analysis of smaller, polluted, or deteriorated samples. Nevertheless, there are methodological and ethical issues. To provide credible and legitimate forensic evidence, rigorous validation and standardization of NanoPCR techniques are vital. The article addresses the relevant ethical and methodological aspects in forensic casework while examining the integration of nanotechnology into PCR.

Rapid and Reagent-Free Analysis of Dried Blood Spot by Paper Spray Mass Spectrometry Reveals Sex: Implications in Forensic Investigations.

Identifying sex from an unknown dried blood spot (DBS), especially when the corpse remains undiscovered, often provides valuable evidence in forensic casework. While DNA-based sex determination is a reliable method in forensic settings, it requires expensive reagents and is time-consuming. To develop a rapid reagent-free blood test for sex, we employed paper spray ionization mass spectrometry (PSI-MS) to capture sex-discriminatory lipid profiles from 200 DBS samples comprising 100 males and 100 females. We conducted a supervised machine learning (ML) analysis on all detected lipid signals to hunt biomarkers of sex within the data set. This analysis unveiled significant differences in specific sphingomyelin and phospholipid species levels between male and female DBS samples. Using the parsimonious set of 60 lipid signals, we constructed a classifier that achieved 100% overall accuracy in predicting sex from DBS on paper. Additionally, we assessed three-day-old air-exposed DBS on glass and granite surfaces, simulating the typical blood samples available for forensic investigations. Consequently, we achieved ∼92% overall sex prediction accuracy from the holdout test data set of DBS on glass and granite surfaces. As a highly sensitive detection tool, PSI-MS combined with ML has the potential to revolutionize forensic methods by rapidly analyzing blood molecules encoding personal information.

IForensic, multicentric validation of digital whole slide images (WSI) in forensic histopathology setting according to the College of American Pathologists guidelines.

Pathology has benefited from the rapid progress of image-digitizing technology during the last decade. However, the application of digital whole slide images (WSI) in forensic pathology still needs to be improved. WSI validation is crucial to ensure diagnostic performance, at least equivalent to glass slides and light microscopy. The College of American Pathologists Pathology and Laboratory Quality Center recently updated internal digital pathology system validation recommendations. Following these guidelines, this pilot study aimed to validate the performance of a digital approach for forensic histopathological diagnosis. Six independent skilled forensic pathologists from different forensic medicine institutes evaluated 100 glass slides of forensic interest (80 stained with standard hematoxylin and eosin, 20 with special staining), including different organs and tissues, with light microscopy (Olympus BX51, Tokyo, Japan). Glass slides were scanned using the AperioGT 450 DX Digital Slides Scanner (Leica Biosystems, Nussloch, Germany). After two wash-out weeks, forensic pathologists evaluated WSIs in front of a widescreen using computer devices with dedicated software (O3 viewer, O3 Enterprise, Zucchetti, Trieste, Italy). Side-by-side comparisons between diagnoses performed on tissue glass slides versus WSIs were above the threshold stated in the validation guidelines (mean concordance of 97.8%). CSUQ Version 3 questionnaire showed high satisfaction for all pathologists (mean result: 6.6/7). Our institutional digital forensic pathology system has been validated for practical casework application. This approach opens new scenarios in practical forensic casework investigations, such as sharing live histological ex-glass slides online, as well as educational and research perspectives, with improving impacts on the whole daily workflow.

Forensic document examination: a global snapshot

Abstract We are delighted to have been invited to be guest editors for this special issue on forensic document examination, a forensic science discipline that has had a long history of use in both criminal and civil investigations. The work of the forensic document examiner (FDE) can encompass handwriting (including signature) comparisons, and examinations and evaluations of physical components of questioned documents such as paper, ink, toner and impressions (of writing and stamps) to answer questions of authenticity or source. A debate regarding the validity and reliability of forensic handwriting examination and other forensic comparison techniques that rely on human cognition and decisionmaking has been ongoing for several years. Furthermore, the risk of cognitive bias in forensic science generally and forensic handwriting examination specifically has been identified in the published literature. Despite a declining reliance on handwritten signatures for business transactions, and increased use of digital technologies for both formal and informal communication, handwriting and signature comparisons and examinations of the components of physical documents still play an important role in forensic casework. It has been only in relatively recent years that significant changes to the paradigm, particularly for handwriting examinations, have occurred, with a greater appreciation of the need to understand and define the scientific basis of the work. Technological developments have led to more objective approaches to handwriting examinations, and the ability to explore in greater detail the physical components of documents. Additionally, topics such as evidence interpretation, reporting and quality assurance are as relevant as ever for the FDE. This special issue showcases research and commentary across a range of forensic document examinations and topics, demonstrating the continued relevance and shifting focus of the field.

A Ge.F.I. Collaborative Study: Evaluating Reproducibility and Accuracy of a DNA-Methylation-Based Age-Predictive Assay for Routine Implementation in Forensic Casework.

The increasing interest in DNA methylation (DNAm) analysis within the forensic scientific community prompted a collaborative project by Ge.F.I. (Genetisti Forensi Italiani). The study evaluated a standardized bisulfite conversion-based Single Base Extension (SBE) protocol for the analysis of the methylation levels at five age-predictive loci (ELOVL2, FHL2, KLF14, C1orf132/MIR29B2C, and TRIM59). The study encompassed three phases: (1) setting up and validating the protocol to ensure consistency and reproducibility; (2) comparing fresh peripheral blood with blood spots; and (3) evaluating sources of intra- and inter-laboratory variability. Samples from 22 Italian volunteers were analyzed by 6 laboratories in replicates for a total of 528 records. From phase I emerged that the choice of genetic sequencer significantly contributed to inter-laboratory data variation, resulting in separate regression analyses performed for each laboratory. In phase II, blood spots were found to be a reliable source for DNAm analysis, despite exhibiting increased experimental variation compared to fresh peripheral blood. In phase III, a strong correlation between the individual's predicted and true ages was observed across different laboratories. Analysis of variance (ANOVA) of the residuals indicated that one-third of the total variance could be attributed to laboratory-specific factors, whereas two-thirds could be attributed to inter-individual biological differences. The leave-one-out cross-validation (LOO-CV) method yielded an overall mean absolute deviation (MAD) value of 4.41 years, with an average 95% confidence interval of 5.24 years. Stepwise regression analysis proved that a restricted model (ELOVL2, C1orf132/MIR29B2C, and TRIM59) produced results virtually indistinguishable from the five-loci model. Additionally, the analysis of samples in replicates greatly improved the fit of the regression model, balancing the slight effects of intra-laboratory variability. In conclusion, the bisulfite conversion-based SBE protocol, combined with replicate analysis and in-lab calibration of a regression-prediction model, proves to be a reliable and easily implementable method for age prediction in forensic laboratories.

Postmortem distribution of mitragynine and 7-hydroxymitragynine in 51 cases.

The prevalence of mitragynine (kratom) in forensic toxicology casework has steadily increased over time. Readily available and currently legal, mitragynine is widely used for its stimulant and, depending on concentration, sedative effects. Our laboratory analyzed various fluid and tissue specimens from 51 postmortem cases to investigate the distribution of mitragynine and its active metabolite 7-hydroxymitragynine. Central and peripheral blood concentrations were compared, with an average heart blood to femoral blood ratio being 1.37 for mitragynine and 1.08 for 7-hydroxymitragynine. This ratio >1.0 suggests that mitragynine has some propensity toward postmortem redistribution; however, the difference in concentrations of mitragynine and 7-hydroxymitragynine is not statistically significant. Large average mitragynine to 7-hydroxymitragynine ratios of 30.9 in femoral blood and 32.4 in heart blood were observed compared to average ratios of 14.8 in vitreous humor and 16.9 in urine. In addition, the stability of these two compounds was investigated in both matrix and organic solvent. When stored refrigerated (4°C), mitragynine was stable for up to 30 days and 7-hydroxymitragynine was stable for up to 7 days with an analyte loss of <20%. Following 60 days of refrigerated storage, 7-hydroxymitragynine concentrations dropped over 50% from initial concentrations. Methanolic preparations of mitragynine and 7-hydroxymitragynine were stable following 3 months of storage at -20°C.

Complex kinship testing using the MGIEasy Pa-SNPs genotyping kit.

Disaster victim identification and criminal investigations have intensified the demand of complex kinship testing. Compared to close relatives, distant relatives share fewer identical-by-descent genetic segments; therefore, more genetic markers are required to improve the system effectiveness. Driven by the progress of next-generation sequencing, several commercial or in-house panels, including a large number of genetic markers, have been developed and applied in forensic caseworks. However, few efficient panels are available for first cousins (FC) kinship testing. Here, we adopted the MGIEasy Pa-SNPs genotyping kit, a two-step multiplex PCR strategy to detect 2,009 SNPs, and evaluated their system effectiveness in complex kinship analysis. Samples from 10,000 pairs of relatives and unrelated individuals were simulated to evaluate the system power. Simultaneously, real samples were used to further confirm this, including 72 pairs of full siblings (FS), 52 pairs of uncle/aunt/-niece/nephew (UN), 92 pairs of FC, 79 pairs of first cousin once removed (1C1R), and 780 pairs of unrelated individuals. The results showed that this kit was sufficiently powerful in FS, UN, and FC versus unrelated kinship testing and could also discriminate part of 1C1R relatives against unrelated individuals. This method was also powerful in the kinship determination of FS versus UN, FS versus FC, FS versus 1C1R, and UN versus 1C1R kinship testing but had limited power to determine UN versus FC and FC versus 1C1R relationships. This study provides an effective strategy and guidance for complex kinship analysis in forensic practice.

Autopsy characteristics of deaths due to pulmonary thromboembolism in northern and western denmark: a 10-year retrospective study

AbstractBecause pulmonary thromboembolism (PTE) has an inherent high risk of sudden and unexpected death, this condition is a classic entity in forensic casework. The purpose of this study was to elucidate the characteristics surrounding deaths from PTE. We conducted a retrospective study from 2010 to 2019 at the Department of Forensic Medicine in Aarhus, Denmark. We recorded demographic characteristics, risk factors, comorbidities, and autopsy findings, including BMI. Furthermore, we contextualized the role of forensic autopsy in terms of determining the correct cause of death (COD).Among the 3,572 autopsies, 58 had PTE as the main COD (1.6%), whereas only 0.3% of the deaths in the Danish COD registry were attributed to PTE in the same period. The decedents had a mean age of 52 years (range 19–87), and although the majority had preexisting comorbidities, approximately one-third died suddenly and unexpectedly. Additionally, more than half (35/58) of the decedents died in an out-of-hospital setting, and only a few of these (6/35) reported symptoms prior to death, underscoring the insidiousness of the condition. We identified a mean BMI of 32.7 among the decedents, with more than half of them (30/58) having a BMI ≥ 30.In conclusion, obesity is a major risk factor for fatal PTE. The blurred clinical presentation of PTE underscores the importance of an autopsy to determine the correct COD, and with an increased autopsy rate, the true prevalence may well be higher.

Benchmarking for genotyping and imputation using degraded DNA for forensic applications across diverse populations

Advancements in sequencing and laboratory technologies have enabled forensic genetic analysis on increasingly low quality and degraded DNA samples. However, existing computational methods applied to genotyping and imputation for generating DNA profiles from degraded DNA have not been tested for forensic applications. Here we simulated sequencing data of varying qualities–coverage, fragment lengths, and deamination patterns–from forty individuals of diverse genetic ancestries. We used this dataset to test the performance of commonly used genotype and imputation methods (SAMtools, GATK, ATLAS, Beagle, and GLIMPSE) on five different SNP panels (MPS-plex, FORCE, two extended kinship panels, and the Human Origins array) that are used for forensic and population genetics applications. For genome mapping and variant calling with degraded DNA, we find use of parameters and methods (such as ATLAS) developed for ancient DNA analysis provides a marked improvement over conventional standards used for next generation sequencing analysis. We find that ATLAS outperforms GATK and SAMtools, achieving over 90 % genotyping accuracy for the four largest SNP panels with coverages greater than 10X. For lower coverages, decreased concordance rates are correlated with increased rates of heterozygosity. Genotype refinement and imputation improve the accuracy at lower coverages by leveraging population reference data. For all five SNP panels, we find that using a population reference panel representative of worldwide populations (e.g., the 1000 Genomes Project) results in increased genotype accuracies across genetic ancestries, compared to ancestry-matched population reference panels. Importantly, we find that the low SNP density of commonly used forensics SNP panels can impact the reliability and performance of genotype refinement and imputation. This highlights a critical trade-off between enhancing privacy by using panels with fewer SNPs and maintaining the effectiveness of genomic tools. We provide benchmarks and recommendations for analyzing degraded DNA from diverse populations with widely used genomic methods in forensic casework.

Observation of chromatographic differences by non-specialist viewers for one-dimensional gas chromatography and comprehensive two-dimensional gas chromatography output

In the context of forensic investigations, chromatography is used to characterize a sample’s components, providing a chemical pattern to compare with known references which is often presented to individuals without specialized training in analytical chemistry. Comprehensive two-dimensional gas chromatography (GC×GC) has recently become popular in forensic research for analyzing samples such as fire debris samples, drugs, chemical threats, human remains detection, and more. New methods are developed in forensic research regularly, which challenge our view of what may be increasingly complex to convey through scientific communication. This study investigated individuals’ ability to observe differences in images for non-chromatographic photographs, one-dimensional gas chromatography (GC) chromatograms, and comprehensive two-dimensional gas chromatography (GC×GC) contour plots. The goal was to identify whether comparative observations between two outputs were facilitated or hindered when observing GC chromatograms compared to GC×GC contour plots, using photographs as a control. Participants indicated low difficulty in finding differences between pairs of images in all categories. They scored highly at indicating when two images were distinguishable or indistinguishable, with no significant difference between control images and each category. These results support that GC×GC output can be implemented in expert testimony without challenges over traditional one-dimensional techniques. Ongoing research should avoid statements that GC×GC may facilitate or hinder juror comprehension, as the results currently indicate no significant benefit or drawback. Additional research is needed to improve understanding of how technique explanation could aid expert witness testimony to better evaluate how this increasingly common technique will fit into future forensic casework opportunities.

How to best assess shedder status: a comparison of popular shedder tests.

"Shedder status" describes the inherent variation between individuals to leave touch DNA on a surface through direct contact. Depending on the amount and quality of DNA or cellular deposition, individuals are typically deemed high, intermediate, or low shedders. Although many shedder tests have been described, variability in study design and categorisation criteria has limited the ability of researchers to accurately compare results, as well as accrue the necessary population data. As activity level reporting becomes more common, the need for reliable and standardised testing increases. To assess reproducibility, this study compared shedder status data generated by six participants using three different shedder tests, as modified from the literature. This involved DNA quantification and profiling of a handprint made on a glass plate, DNA quantification and profiling of a grip mark made on a plastic conical tube, and cell scoring of a Diamond™ Dye-stained fingermark. All participants washed and dried their hands fifteen minutes before each deposit. To assess the impact of behaviour on shedder designation, participants either refrained from activity or went about their daily tasks during this wait. The shedder status of participants changed between tests, as DNA-based testing often generated lower shedder statuses than cell scores. Further, when different categorisation methods were applied to a single test, intra-person variability increased as the number of shedder designations increased from two (low/high) to five (low/low-intermediate/intermediate/intermediate-high/high). Moving forward, the utilisation of a single shedder test and standardised categorisation criteria is needed to employ shedder testing in forensic casework.

Towards the identification of body fluids using RT-LAMP isothermal amplification coupled with CRISPR-Cas12a

While often necessary in sexual assault cases, confirmatory identification of body fluids can be a lengthy and/or costly process. In particular, the detection of vaginal fluid and menstrual fluid in forensic casework is limited to endpoint reverse-transcription PCR to detect fluid-specific messenger RNA (mRNA) markers as there are no robust chemical or enzymatic techniques available for these fluids. Similarly, testing for rectal mucosa is not possible with standard methods, the presence of which would provide probative value in cases of alleged anal penetration, although mRNA-based markers have recently been described. Reverse-transcription loop-mediated isothermal amplification (RT-LAMP) is an alternative technique that enables detection of mRNA at a single temperature (usually 60–65℃) for 10–30 minutes and has comparable sensitivity to PCR. We describe the coupling of RT-LAMP amplification (60℃ for 30 minutes) with CRISPR-mediated fluorescent detection of the body fluid specific mRNA markers MMP3 (menstrual fluid), CYP2B7P (vaginal material), TNP1 (spermatozoa), KLK2 (semen), and MUC12 (rectal mucosa). Following temperature optimization and final selection of RT-LAMP-CRISPR assays, their specificity across circulatory blood, buccal, menstrual fluid, vaginal material, semen, and rectal mucosa was assessed. Most assays were specific for their intended target body fluid, although MMP3 and CYP2B7P were detected in some rectal mucosa samples, the latter of which has been observed previously in the literature. A preliminary sensitivity assessment in target fluids was determined by a dilution series over six logs of RNA input. A range of assay approaches were investigated to develop a protocol suitable for use in a forensic screening laboratory. This included the determination of fluorescent assay results by eye, use of lyophilised reagents, and RT-LAMP and CRISPR reactions undertaken in one-tube in a lower resource setting.

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.

Animal family discrimination from hair using ATR-FTIR and machine learning methods for applications in illegal wildlife trafficking.

Wildlife forensics plays a pivotal role in the combating illegal trafficking, supporting biodiversity conservation, and aiding in the identification of animals in wildlife. Animal hair, often found in trafficking crimes, serves as vital biological evidence that can provide significant information for animal identification. This study proposes a novel method integrating machine learning classifiers with Fourier transform infrared (FTIR) spectroscopy in attenuated total reflectance (ATR) mode to enhance the effectiveness of animal identification in wildlife forensic casework. Additionally, compound microscopy has also been utilized as a preliminary tool to perform morphological analysis of hair samples from four animal families, including Bovidae, Cervidae, Elephantidae, and Felidae. Further, chemical profiling through spectral data revealed significant overlapping peaks between family Bovidae and Cervidae. The classification experiment provides the random forest (RF) classifier as the most effective for family discrimination model. This research offers valuable insights for wildlife forensics by improving the identification accuracy of unknown hair samples, thus enhancing the overall effectiveness in forensic investigations.

Internal validation of the Precision ID GlobalFiler NGS STR panel v2 kit with locus-specific analytical threshold, and with special regard to mixtures and low template DNA detection

We performed an internal laboratory validation of the Precision ID GlobalFiler NGS STR panel v2 kit to assist the introduction of the technology into the routine forensic casework practice. The study was designed and evaluated based not only on the key validation standards like sensitivity, stability, reproducibility, repeatability, mixture, and concordance, but we also tested the effect of reduced input DNA, we measured and applied locus-specific analytical threshold values, tested two different PCR cycle conditions, sequence artifacts and stutters were also analysed. During the study we also tested the new method on real casework samples. The sensitivity study confirmed that adding 500 pg template DNA for library preparation can be optimal at base PCR cycle number (that was 24), because the measured average heterozygote balance was not lower than 0.82, and each allele was detected above the analytical threshold. However, contrary to previous communications, increasing the PCR cycle numbers up to 28 has not resulted the significant elevation of the heterozygote imbalance. According to our results, raised PCR cycle condition (i.e. 28) is appropriate at or below 150 pg total input DNA. For most loci, the calculated AT was lower than the manufacturer’s recommended. Applying the newly established ATs with raised PCR cycle conditions the allele detection sensitivity and reliability increased. We observed allele dropouts only at the 15 pg template DNA experiments with 5 % frequency, that is better to previously published studies. This result indicates that this low amount of DNA (i.e. 15 pg) could be a minimum limit of template input for a potentially successful analysis. In the mixture study the minor contributor could be detected up to 1:19 mixture ratio. We detected minor alleles in all measurements and concentrations above the threshold if the template DNA were fixed and only SNP differences were observed between the same alleles of the contributors. To test concordance between the new method and traditional STR genotyping we analysed 58 Hungarian individual samples in parallel. Nearby the detected 248 different length-based alleles on the 31 loci in the sample pool we revealed additional 75 sequence variant alleles, that represent an approximately 23 % increase in the total number of observed alleles. The casework study confirmed that the Precision ID GlobalFiler NGS STR panel v2 kit is effective even in genotyping degraded samples with extremely low levels of DNA, if we apply elevated cycle number for library preparation and use locus-specific analytical thresholds.

Double Designers: Detection of Bromazolam and Metonitazene in Postmortem Casework.

The identification of novel psychoactive substances (NPSs) in casework at the Los Angeles County Department of Medical Examiner (LACDME) is constantly evolving. The case detailed herein marks the first detection of metonitazene in forensic casework at the LACDME which occurred in August 2023. Furthermore, bromazolam was found in the decedent's system and both substances were identified in drug evidence collected at the death scene. No other drugs were detected and the manner and cause of death were determined as accidental due to effects of bromazolam and metonitazene. The concentrations detected were 1.6 ng/mL and 4.4 ng/mL of metonitazene in the jugular blood and femoral blood, respectively, and 93 ng/mL of bromazolam in the femoral blood. Constraints in screening techniques conducted by toxicology laboratories create challenges in which numerous NPSs available on the illicit drug market can go undetected. Even if labs detect an NPS in their screening methodology, confirmation methods might not cover every NPS, given the impracticality of labs keeping pace with validations as new NPSs emerge in casework. The significance of testing medical evidence collected at death scenes by drug chemistry analysis becomes crucial when initial toxicology results are negative. In cases where there is evidence of potential drug paraphernalia this is especially true as it can be pivotal in determining the cause and manner of death.

Searching medieval human remains using ground penetrating radar: A case study in Venosa (Basilicata, Southern Italy)

Controlled forensic geophysical research involving GPR has proven to be a valuable resource, and the information gathered from these studies has been applied to forensic casework. The probability of detecting a grave for a longer postmortem interval differs with the soil type and the materials added to the grave with the body. In the studied case a detailed GPR survey was conducted in the Basilica della Trinità at Venosa a village located about 40 km north from Potenza (Basilicata, Italy).Unfortunately during the restoration works of the Basilica, there was a cement spill inside a sarcophagus containing human remains. The necessity to perform the genetic analysis of medieval human remains to reconstruct the distribution of the original line of descent of the Norman noble families aimed the need to understand whether or not there was a body inside the sarcophagus and, if so, its exact position.The radar profiles from this survey showed the clear amplitude contrast anomalies, emanated from the corpses. The strongest amplitude contrasts are observed at around 0.2–0.5 m depth which is consistent with the depth of the buried corp.

T2-weighted spoiled gradient echo MRI for forensic age estimation: a study on knee growth plates

The timing of growth plate fusion is a key indicator for age estimation and is primarily used in forensic investigations. On the other hand, non-ionizing techniques such as MRI are being developed to provide safer and more ethical evaluations in forensic casework. This study aims to evaluate the closure process of growth plates in the distal femoral and proximal tibial epiphyses using Multiple Echo Recombined Gradient Echo (MERGE) MRI sequences and provide age estimation data based on staging methods for forensic purposes. We retrospectively analyzed 559 patients (294 males, 265 females, aged 8–25 years) diagnosed with trauma and knee pain at Tepecik Training and Research Hospital from 2016 to 2019. MRI scans were performed using a 1.5-T system with MERGE sequences and evaluated by two observers using a new staging system. Observer agreement was assessed using Cohen’s κ test, yielding high agreement values (κ > 0.8). Positive correlations were found between age and ossification stages (p < 0.001). Minimum age thresholds for stages 5a and 5b of the distal femoral epiphysis were 16 and 18 years for females and 17 and 19 years for males, respectively. For the proximal tibial epiphysis, the minimum ages for stages 5a and 5b were 15 years for females and 17 years for males. The MERGE sequence provides a viable method for assessing skeletal maturity in living individuals with significant ethical advantages due to non-ionizing radiation. This study supports the potential application of the MERGE sequence in forensic age estimation, demonstrating high observer agreement and consistency. Future research should focus on comparing different sequences and populations to enhance the methodology’s applicability.