National Research Institute of Police Science

This interdisciplinary essay explores the integration of Forensic Anthropology and Forensic Entomology to analyze shallow graves, focusing on decomposition processes, necrophagous insect succession, and environmental factors in forensic contexts, particularly in Northeast Brazil. It highlights the challenges of post-mortem interval (PMI) estimation due to regional variability and the paradox of insect colonization in shallow burials. The study emphasizes the need for localized research, standardized protocols, and technological advancements like AI and 3D modeling to enhance forensic accuracy. Collaboration between institutions and multidisciplinary training is advocated to strengthen forensic methodologies and legal evidence. Keywords: Forensic Anthropology, Forensic Entomology, Shallow Graves, Post-Mortem Interval (PMI), Interdisciplinary Forensic Investigation.

In this study, we present a genetic diagnostic device with a four-stepwise logarithmic dilution capability for rapid and reliable detection of target nucleic acids in a single operation using the colorimetric loop-mediated isothermal amplification (LAMP) method. An innovative feature is the confluent point with differing microchannel heights ensuring the synchronized inflow of liquids while preventing backflow, even under large volumetric flow rate variations (10-10 000-fold). This enabled the independent generation of each dilution factor under constant pressure. Furthermore, an integrated asymmetric micromixer effectively mixed two liquids under laminar flow conditions, enabling simultaneous dispensing of the mixed solution at uniform concentrations into five microchambers for each dilution factor. Additionally, a permanent stop valve in the outlet of each microchamber prevented leakages, minimizing the waste of valuable samples and reagents. We demonstrate that diluted samples were accurately prepared at the intended logarithmic dilution factors in a single operation using purified cannabis seed DNA, achieving detection sensitivity similar to that of conventional turbidity-based LAMP assays. Moreover, we used crudely extracted cannabis resin DNA, which contains several gene amplification inhibitors, successfully detecting the target nucleic acids in a single test. Overall, this versatile device eliminates extensive manual sample preparation and has potential for on-site genetic testing in applications such as infectious disease detection, food safety, and illegal drug testing.

Gait biometrics have recently been adopted in security systems and forensic applications, but issues stemming from the coexistence of viewing and speed variations have not yet been resolved. In this study, we constructed a novel multi-view and multi-speed-mode (walking and running) silhouette/3D gait dataset, which we call the “NRIPS-run dataset,” containing 53 individuals (or identities) derived from treadmill silhouette sequences under four speed conditions (walking: 3 and 5 km/h; running: 7 and 9 km/h). Based on the dataset, cross-view and cross-speed-mode matching including running speed conditions, as well as state-of-the-art reported methods on deep learning-based gait recognition, were evaluated in both identification and verification scenarios. The analyses revealed that analysis accuracy tended to be slightly higher under running speed conditions than under walking speed conditions for same speed comparisons, whereas cross-view and cross-speed-mode matchings remained challenging in both scenarios. Our findings are expected to accelerate further developments in vision-based running gait biometrics.

The metabolism of the highly potent synthetic opioids metonitazene, etonitazene, and protonitazene was investigated in fresh human hepatocytes. In the hydrolyzed culture medium, N-desethyl-, N,N-di-desethyl-, O-desalkyl-, N-desethyl-O-desalkyl-, N,N-di-desethyl-O-desalkyl-, and N-oxidated metabolites were detected as phase I metabolites, whereas in the unhydrolyzed culture medium, O-glucuronides of phase I metabolites with O-dealkylation were detected as phase II metabolites. The detected phase I metabolites were identified by comparing their analytical data with those of synthesized authentic standards. In contrast, phase II metabolites were identified by comparing their analytical data with those of the glucuronidated products formed by the incubation of the corresponding substrates with human liver microsomes in the presence of uridine diphosphate glucuronic acid. In addition to the aforementioned metabolites, some putative N-ethyl-N-(1-glucuronyloxyethyl) metabolites were detected in the unhydrolyzed culture medium. Purification and hydrolysis experiments revealed that N-ethyl-N-(1-glucuronyloxyethyl) metabolites formed the corresponding N-desethyl metabolites via unstable N-ethyl-N-(1-hydroxyethyl) metabolites during enzymatic hydrolysis.

The identification of vertebrate species is important in numerous fields such as ecology, archaeology, and food and forensic sciences. Real-time quantitative PCR (qPCR) assays specific for one vertebrate species are promising approaches for species identification, although there are several drawbacks such as difficulty determining whether the detected DNA is authentic or a contaminant. Here, we describe a qPCR assay specific for vertebrate mitochondrial DNA (mtDNA) which can overcome these drawbacks. Since we found that mitochondrial 16S rRNA contains regions that are perfectly (not highly) conserved across virtually all vertebrates, but are variable in invertebrates, we were able to design a vertebrate-specific qPCR assay by placing primers/probe within these regions. The specificity and accuracy of this assay were validated with representative vertebrate and invertebrate samples. This assay detected DNA from all vertebrate samples, but not from any invertebrate samples. In addition, this assay was able to quantify vertebrate mtDNAs as accurately as previously reported species-specific qPCR assays. The results demonstrated it is feasible to quantify vertebrate mtDNA specifically and accurately in a sample. This means that it is possible to determine the ratio of specific vertebrate species mtDNA to total vertebrate mtDNA in a sample. In conjunction with this assay as an endogenous internal control, species-specific qPCR assays will allow for the robust identification of vertebrate species.