Earticle

Toluene is an aromatic hydrocarbon widely employed as an industrial solvent in adhesives and paints. Due to its broad availability and low cost, it ranks among the most frequently abused volatile substances worldwide. With repeated inhalation, toluene affects the central nervous system, inducing euphoria, intoxication, and hallucination, while its high lipophilicity facilitates penetration of the blood–brain barrier and accumulation in lipid-rich tissues. Given these properties, high-dose inhalation of toluene may lead to direct fatal intoxication, as well as indirect fatalities arising from accidents associated with hallucinatory impairment. In most toluene-related deaths, toxicological interpretation typically relies on scene investigation, the presence of paraphernalia, and reported blood concentrations of toluene. However, in indirect fatalities, interpretation based solely on blood toluene concentrations remains controversial due to ongoing biological processes. In this study, we investigated a fatal case involving a 56-year-old male with a history of toluene abuse. Postmortem specimens, including heart blood, peripheral blood, urine, lung and brain tissue, were analyzed for toluene using solid-phase microextraction gas chromatography–mass spectrometry (SPME-GC/MS) with a standard addition method. Toxicological analysis revealed a markedly elevated concentration of toluene in brain tissue (10.04 mg/kg). Heart and peripheral blood contained 1.94 mg/L and 1.27 mg/L of toluene, respectively. Urine and lung tissue exhibited a relatively low concentrations of 0.14 mg/L and 1.89 mg/kg, respectively. This case analysis, based on an understanding of the distributional characteristics and toxicological mechanisms of toluene, suggests the forensic interpretability of volatile hallucinogenic substances as potential indirect causes of death and is expected to contribute to toxicological assessments in future similar cases.

Fentanyl analogs are highly potent synthetic opioids active at very low doses and have been implicated in numerous overdose deaths, particularly in the United States. Although serious social problems caused by the abuse of fentanyl analogs have not yet been reported in Korea, possibly remains a risk of their introduction into the country. Thus, the establishment of analytical methods for fentanyl analogs in biological samples has become necessary. In this study, we developed simultaneous analytical methods for the detection of 22 fentanyl analogs and their metabolites in human hair using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Specificity, selectivity, limits of detection (LOD), limits of quantification (LOQ), linearity, precision, accuracy, matrix effect, recovery, and process efficiency were evaluated, and all results were acceptable. Additionally, the distribution of fentanyl analogs in the hair of drug abusers from 2020–2024 was investigated. Fentanyl was detected in 204 cases, with the highest frequency observed in 2021, followed by a decreasing trend in subsequent years. A rare case involving both fentanyl and remifentanil was identified in the hair of a 48-year-old female nurse, demonstrating the applicability of this method for detecting fentanyl analogs in forensic investigations.

Russula subnigricans (R. subnigricans) is a toxic mushroom mainly found in East Asia. Ingestion of R. subnigricans can cause a wide range of symptoms, from mild gastrointestinal disturbances such as abdominal pain, nausea, vomiting, and diarrhea, to severe conditions like rhabdomyolysis accompanied by acute renal failure, electrolyte imbalance, and even death. The toxic compound responsible for R. subnigricans poisoning is known to be cycloprop-2-ene carboxylic acid. However, due to its instability, cyclopropylacetyl-(R)-carnitine is recognized as a specific marker for R. subnigricans intoxication. A 64-year-old man presented to the emergency department with vomiting and diarrhea after consuming wild mushrooms collected in the mountains. He subsequently developed rhabdomyolysis and died three days later. Blood samples from the patient and the ingested mushrooms were analyzed to identify toxic substances. Cyclopropylacetyl-(R)-carnitine was detected in both samples using liquid chromatography–quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Based on these toxicological findings, the ingested mushrooms were identified as R. subnigricans, and the cause of death was determined to be rhabdomyolysis induced by toxic mushroom ingestion.

Synthetic dyes typically contain impurities formed during the manufacturing process, including intermediates, by-products and colored impurities called as subsidiary colors. Among synthetic dyes, azo dyes were synthesized similarly by diazotization and coupling reactions, which can produce similar subsidiary colors. Since azo dyes and their subsidiary colors are known to possess carcinogenic and other toxic properties, appropriate control measures need to be required. In this study, we developed an analytical method for the simultaneous determination of 10 subsidiary colors derived from azo dyes using high performance chromatography-diode array detector (HPLC-DAD), and monitored subsidiary colors and Food Yellow No. 5 (sunset yellow FCF) in commercially available raw materials and beverages. The developed method can successfully detect subsidiary colors at low level of 0.012―0.068 mg/L, and show acceptable performances for accuracy and precision. As percentage contents of subsidiary colors in commercial beverages containing Food Yellow No. 5 were lower than or comparable to those in raw materials, most of subsidiary colors were not intentionally added to beverages but are presumed to be produced from Food Yellow No. 5. We also found that the percentage contents of subsidiary colors in commercial food colorants satisfied the national and international ‘Specifications and Standards for Food Additives’.

In this study, we examined the DNA analysis status of cases referred to the DNA Analysis Division of the Gwangju Institute of National Forensic Service (NFS) over the past three years, from 2022 to 2024. We also looked into the types of sex crimes and locations where theft incidents primarily occurred, as well as the number of pieces of evidence referred per case. Over the three years, DNA analyses were conducted on 17393, 18206, and 17584 pieces of evidence for 4722, 5098, and 4774 cases each year, respectively. In 2022 and 2023, the highest number of cases and their respective evidence were referred for DNA analysis in May, while in 2024 it was in October. Among all the evidence referred over the three years, evidence related to sex crimes accounted for 30~33.5%, with an average of about 6.9 pieces of evidence per case. Among sex crimes, evidence for sexual assault cases averaged 66% over the three years, and sexual abuse cases accounted for 21%. Furthermore, evidence related to theft accounted for 33~37%, with an average of about 3.3 pieces of evidence per case. Among the evidence for theft cases, vehicle-related evidence averaged 45% over the three years, residential evidence was 25%, and multi-use facilities accounted for 24%. Through this statistical analysis of DNA examinations, we could identify trends and patterns of the referred cases and the average number of evidence pieces per case type, ultimately aiming to promote the advancement of forensic science through efficient DNA analysis.

Several commercial kits are available for Y-chromosome short tandem repeat (Y-STR) haplotyping for forensic purposes. The PowerPlex® Y23 System (Promega Corp., Madison, MI, USA) and the Yfiler™ Plus PCR Amplification Kit (Thermo Fisher Scientific, Waltham, MA, USA) were recently released and has been used worldwide in several populations. The Y-STR multiplex systems may fail to detect alleles with stochastic or extreme repeat numbers that fall outside the predefined allelic bins. Here, we report unusually a non-fractional off-ladder allele (allele 7, short repeats of 7-repeat) at DYS576 locus found in the forensic casework. To ensure data reliability, cross-analysis were performed using the aforementioned two different Y-STR multiplex kits and DNA sequencing were employed. These findings suggest that the variant may not be rare within the Korean population, necessitating extensive validation of Y-STR multiplex systems for forensic applications in Korea.

Oleander(Nerium oleander), which contains toxic substances of oleandrin, blooms with white, yellow, and pink flowers. In this study, we investigated how much the genes differ according to flower color within oleander species. A total of 14 oleander individuals were used, 10 individuals with known flower color(two of white flowers, one of yellow flowers, and seven of pink flowers) and 4 individuals with unknown flower color. The genetic markers used in this study are five chloroplast markers(psbA-trnH intergenic spacer(IGS), trnL-trnF IGS, trnL intron, rbcL, matK) and four nuclear markers(intergenic transcribed spacer region(ITS), 18S ribosomal RNA(rRNA), phenylalanine ammonia-lyase(PAL), xanthine dehydrogenase(Xdh)). As a result of analyzing nucleotide sequences of these genetic markers from 14 individuals, three chloroplast genetic markers of psbA-trnH IGS, trnL-trnF IGS, and trnL intron showed some differences and three markers of rbcL, matK, and 18S rRNA did not. For the ITS sequence, a total of 84 clones(6 clones each from 14 oleander samples) were obtained using the vector cloning method, resulting in 79 oleander ITS sequences, and the remaining 5 were fungal ITS sequences. Even within a single sample, diverse ITS sequences were observed. PAL and Xdh showed duplicated nucleotide sequences of Y, R, S, and W. Four samples of unknown flower color showed identity with individuals with pink(double) flowers in the nucleotide analysis. Distinct sequence variations based on flower color were not consistently observed across all genetic markers. The nucleotide sequences obtained from this study were registered into GenBank of NCBI. The genetic distance was the highest with the ITS marker, but based on the ease of the experiment, psbA-trnH IGS marker seems to be the best plant barcode in this study.

Body fluid identification is an essential component of forensic interpretation, complementing DNA profiling by providing contextual information on activity-level events at crime scenes. This study evaluates an mRNA profiling method based on DNA/RNA co-extraction using the AllPrepⓇ DNA/RNA Mini Kit and multiplex cDNA PCR. Semen, saliva, and blood samples collected from ten volunteers were stored under refrigerated and frozen conditions and analyzed at multiple time points up to six months. Additional experiments assessed long-term RNA preservation using RNAlaterⓇ(Thermo Fisher Scientific)-treated samples up to twelve months. The overall marker detection rate reached 93%, with no observable cross-reactivity between body fluid specific markers. Field case samples including menstrual secretion, vaginal fluid, and semen were accurately identified even when conventional DNA profiling showed limited findings. These results demonstrate that mRNA profiling using DNA/RNA co-extraction provides robust detection sensitivity, compatibility with routine forensic workflows (~8 hours), and enhanced reliability in interpreting mixed or activity-level biological evidence. This method is suitable for implementation in forensic laboratories as a complementary tool to DNA profiling.

This study analyzes forestfire cases caused by contact between overhead power lines and vegetation from a forensic science perspective. Fire cases in which such contact was determined to contribute to ignition were examined based on on-site investigation results, focusing on damage patterns of power lines, vegetation charring, and electrical traces. The cases were classified into three contact types: (1) long-term vegetation growth causing gradual insulation degradation, (2) tree fall due to strong winds leading to power line breakage, and (3) repetitive wind-induced contact resulting in localized insulation wear. The results show that each contact type exhibits distinct ignition mechanisms and damage characteristics, including short circuits, electrical heating, grounding, and ember generation. These findings demonstrate that fires involving overhead power lines and vegetation should be interpreted through an integrated analysis of power line damage, vegetation condition, and environmental factors. This study provides practical forensic criteria for determining fire causes related to power facilities and vegetation and offers implications for forestfire prevention and fire investigation practices.

Marine incidents and accidents are difficult to objectively reconstruct due to the wide maritime environment and limited observation resources. In particular, unlike large vessels equipped with Voyage Data Recorders (VDR) under International Maritime Organization regulations, small vessels operating in coastal and offshore areas have limitations in securing objective trajectory data during accident investigations. To address this issue, Korea has mandated the installation of Vessel Pass (V-Pass) location transmitters for small vessels; however, research into the device's internal data structure and forensic interpretation remains insufficient. This study analyzes location information stored in V-Pass devices from a digital forensic perspective. It proposes the methodology and necessity of vessel trajectory analysis based on raw data. For this purpose, the storage structures of trajectory parameters, such as latitude, longitude, time, speed, and course, were analyzed using V-Pass terminals manufactured by Samyung ENC Co., Ltd. and GMT Co., Ltd., which are widely used on small vessels in Korea. In addition, a mathematical model for distance calculation and speed and bearing estimation was applied to verify the physical consistency of the reconstructed trajectory data. The results show that although the recording structures differ by manufacturer, vessel trajectories can be reconstructed through regular record structures. The reconstructed trajectories also show consistency with actual navigation patterns. These findings indicate that V-Pass data can serve as meaningful digital evidence for proving vessel movement routes and navigation behavior in maritime accident investigations. This study is significant for presenting a digital forensic analysis framework applicable to small-vessel accident investigations.

Identifying locations where human remains were previously present remains a major challenge in forensic investigations, particularly when remains have been relocated or removed. Decomposition releases body fluids and organic compounds into surrounding soils. These inputs alter soil physicochemical conditions and microbial community structure, generating potential forensic indicators of carcass deposition. This study investigated the depth-resolved (5–20 cm) effects of surface-exposed pig carcass decomposition on soil physicochemical properties and microbial communities under outdoor conditions in the Republic of Korea. Soil samples were collected from a carcass deposition site and two nearby control locations. Soil pH, oxidation–reduction potential (ORP), and electrical conductivity (EC) were measured. Microbial community composition was characterized using 16S rRNA gene sequencing, followed by diversity analyses and linear discriminant analysis effect size (LEfSe). Carcass decomposition significantly altered soil chemistry. Surface soils showed strong alkalization (pH 8.9), intense reduction (ORP −117 mV), and elevated electrical conductivity (531 μS/cm). These effects attenuated with increasing depth, reflecting vertical diffusion of decomposition-derived fluids. Microbiome analysis revealed reduced alpha diversity and a shift toward dominance by copiotrophic taxa, particularly Firmicutes. Beta diversity analysis demonstrated clear separation between carcass and control soils. LEfSe identified several indicator taxa associated with carcass decomposition, including Sporosarcina, Chujaibacter, Lapillicoccus, Glutamicibacter, Savagea, and Pseudogracilibacillus. These taxa exhibited distinct depth-dependent abundance patterns within the soil profile. These findings demonstrate that carcass decomposition generates depth-resolved microbial signatures in soil. Soil microbiome profiling shows strong potential as a complementary forensic approach for identifying environments influenced by carcass deposition.

Indoor homicide scenes present significant challenges to forensic investigation due to complex bloodstain patterns, the spatial distribution of evidence, and the urgent need for scene preservation before inevitable environmental alteration occurs. This study comparatively evaluates three-dimensional (3D) crime scene reconstruction techniques—360-degree cameras (RICOH THETA Z1), iOS LiDAR-based mobile scanning (iPhone 12 Pro or later; iPad Pro 13-inch M4 used in this study, with Polycam and VR visualization via Gravity Sketch), and a professional laser scanner (FARO Focus Laser Scanner)—through a simulated indoor bloodstain crime scene. A mock homicide scene was constructed with forensic blood substitution and evaluated across three dimensions: spatial reconstruction fidelity including a single wall-segment comparison, operational efficiency under time-sensitive conditions, and applicability as immersive training materials. Results showed that the FARO laser scanner provided the highest spatial fidelity, with a measured wall-segment value of 1.796 m compared with a tape-measured value of 1.800 m (relative difference -0.22%) in the single comparison performed, while the 360-degree camera offered the fastest deployment (~6 min) and iOS LiDAR provided a practical balance of 3D spatial data and accessibility (~12 min). Based on these findings, a tiered utilization framework combining all three techniques is proposed, along with discussion of VR-based reconstructions as a platform for standardized forensic education.

This study investigates the thermal and electrical transient responses of Partial Disconnection faults in low-voltage indoor wiring, a major hidden cause of electrical fires. While parallel short-circuits easily trigger protection devices, series arcs from Partial Disconnection create severe localized Joule heating without significantly altering the overall root-mean-square (RMS) current, creating a critical safety blind spot. To thoroughly analyze this phenomenon, a dynamic impedance model and a 2-node heat transfer equivalent thermal network were developed using MATLAB/Simulink. Simulations systematically compared the instantaneous heat generation and temperature trajectories of copper conductors and PVC insulation under linear and non-linear (SMPS) loads at an identical active power of 300W. The results demonstrate that under non-linear loads, impulsive peak currents cause the instantaneous heat generation to surge drastically compared to linear loads. Consequently, the temperature of the PVC insulation rapidly exceeds its ignition threshold, reaching over 300℃ within 40 seconds, inevitably leading to early ignition. Despite this severe thermal runaway, conventional molded case circuit breakers and arc fault circuit interrupters fundamentally fail to detect the fault, as the RMS current remains strictly below the tripping threshold. Ultimately, this study quantitatively proves the critical vulnerability of current protection systems against Partial Disconnection, emphasizing the urgent need for advanced early detection algorithms.