Earticle

To quantify the carboxyhemoglobin (CO-Hb) concentration of a forensic biospecimen (commonly blood or tissue sample) by headspace gas chromatography (HS-GC), most laboratory protocols entail bubbling carbon monoxide (CO) and nitrogen (N2) gas through the sample to saturate it and then liberate free CO gas. However, despite safety precautions, such as the use of a fume hood, extended exposure to CO imposes significant safety hazards to analysts. Moreover, analysts working in poorly equipped laboratories must pay increased attention during CO bubbling to prevent sample overflow. Such difficulties slow down the procedure tremendously, particularly when multiple samples must be analyzed simultaneously. In this study, adjustments to the conventional approach were made by introducing a given blood sample into a syringe equipped with a three-way valve, which then withdraws CO gas from an airtight gas sampling bag. After rotating the syringe, free CO in the blood is removed by moving the plunger up and down a few times and repeating the procedure with nitrogen gas. The resulting blood sample is then used to prepare a concentration series of CO-Hb blood. The sample preparation time for six samples was reduced by approximately 74 %, and no significant differences in CO-Hb levels were observed compared with the conventional method. This modified approach is expected to facilitate the inexpensive and efficient CO-Hb concentration determination of multitudinous samples for accurate forensic analysis.

Many vehicles equipped with autonomous driving functions have been developed to increase driver convenience and secure safety, and are being driven on actual roads. Various sensors such as camera, radar and lidar to recognize surrounding objects are applied on the autonomous driving-based vehicles, and advanced technology to control the vehicles using data collected from the sensors is grafted on them. To identify the cause of an accident in autonomous vehicles, it is necessary to compare and analyze a large of scenarios. However, there are constraints of time and cost in the traditional field investigation, and as a result, it causes limitations in defect investigation. This paper will present the necessity of autonomous driving simulation and its methodology for analysis of the autonomous driving accident. The simulation software is Prescan which has been developed by SIEMENS.

As crimes and criminal methods become more sophisticated, including attempts to conceal evidence, there are cases where corpses are meticulously and thoroughly hidden. One such example is when skeletal remains are discovered within the cement structures that are being demolished for reconstruction or other purpose. However, it is difficult to detect whether a body has been buried within a cement structure prior to its demolition. In this study, animal corpses were buried in commonly used cement mortar, and the gas components generated during decomposition were examined to assess the possibility of using these components as indicator substances for locating burial sites. Among the various components detected during the decomposition of bodies buried in cement materials, dimethyl disulfide and phenol were distinctively identified. These components show promise as indicators for tracking corpses in the early stages of burial, although the influence of components originating from the surrounding environment cannot be ignored after a long period of time.

Blood pattern analysis is a technique that analyzes the size, location, shape, and distribution of blood pattern distributed at the scene of the incident to reveal the cause of the bleeding, and reconstructs a series of actions in chronological order. At the site of the bloodshed, gush, cast-off, impact spatter, expectorate, which are blood marks caused by projected, are observed in the classification system by the generation mechanism. In order to find the area of the origin of these bloodstains and to reconstruct the site, analysts are training using laser protractors and string connections or using a program called Hemospat to find the convergence point of the space, which is the price position. This study ignored gravity and air resistance, and compared the error value of using the triangular function and Spatter Angle app with using the Hemospat program. As a result of the study, when using the triangular function and Spatter Angle app, error value is derived to be less than 2 cm if the distance is less than 40 cm and the height is less than 120 cm.

Recently, technologies that make static analysis difficult are applied to most malicious codes, and the most representative technologies are packing and obfuscation technologies. Therefore, research on unpacking and deobfuscation techniques is essential for effective static analysis. Therefore, in this paper, an integrated unpacking and deobfuscation automation system was developed to solve this problem, and a 94.9% recovery rate was confirmed through a verification process.

Even now, numerous missing children and their guardians(family) are desperately looking for each other. It is a natural responsibility of the state to make efforts in various ways at the pan-governmental level for their reunion. So far, there are 30,275 missing children registered and managed in the missing children DNA database, and there are 3,232 guardians, which is about 10 times the number of guardians (as of April 11, 2023). Until now, about 630 cases of family reunion have been made directly or indirectly through the missing children DNA database. Some of the main cases are reported in this study.

The identification of fraudulent stamps is an important problem in various fields, such as finance, law enforcement, and customs. In this paper, we propose a reverse engineering analysis of stamps manufactured by a CNC engraving machine, which can provide important information for identifying the production conditions of stamps. We first analyzed the images of a large number of CNC-engraved stamps to extract key features such as stroke width and spacing, which are closely related to the manufacturing process. We then developed a database of known stamp production conditions, which enabled us to identify the production parameters of unknown stamps through a process of feature matching. Our results showed that even when two stamps are produced by the same engraving machine and appear similar in most aspects, small differences in production conditions can be identified and quantified through our feature-based analysis. This makes it possible to distinguish between two stamps with greater reliability, which can be useful in forensic analysis and legal proceedings. Overall, our research demonstrates that reverse engineering analysis of CNC-engraved stamps can be an effective tool for identifying production conditions and improving the reliability of stamp authentication.

In sexual crime cases, it is difficult to obtain a male short tandem repeat (STR) profile from samples with high concentration of female DNA. In the cases, it is important to obtain Y chromosome STR(Y-STR) profile from the samples in order to solve the cases. Occasionally, intact Y-STR profile is found in samples containing the male DNA less than the minimum detection limit in sexual crime cases. At this point, we wonder whether the quantitative value of male DNA was affected by the high concentration of female DNA. Using two Y-STR kits, Y-STR profiles were examined in the mixed DNA samples of female DNA isolated from vaginal fluid and male standard DNA. It was confirmed that high concentrations of female DNA did not affect the acquisition of Y-STR profile in the mixed DNA samples. However, the female DNA affected the quantitative values of male DNA in the samples. This study is expected to contribute to the reliability of obtaining intact Y-STR profile in mixed DNA samples with concentrations below the minimum detection limit for obtaining the Y-STR profile.

Red pepper powder is a necessary ingredient in our culinary culture, using in a variety of dishes such as Kimchi and salted seafood. As the global food landscape expands, the kind of red pepper powder is diversified, leading to an increased consumption trend. FTA was implemented in 2010 and almost agricultural products expected to be fully opened to international trade by the early 2030s. Red pepper powder imported with a low tariff has the potential to trigger a self-sufficiency collapse in the domestic red pepper industry and leading to a fraud of red pepper powder(ex. mislabeling). In response, this study seeks to develop a testing method for discerning the origin of domestic and imported red pepper powder and furthermore aims to mitigate social and economic confusion caused by inaccurate information provision and unjustifiable expenses. This study secured each 60 samples of red pepper powder from domestic and Chinese origin and then a comprehensive literature review guided the selection of components for analysis. Instrumental analyses, involving equipment such as HPLC, UV spectroscopy, ICP, IR-MS, were conducted through necessary pre-treatment. Among the 28 components analyzed, significant differences were observed in fructose, ASTA color value, total polyphenol content, Al, Fe, Na content and nitrogen isotope ratio mass analysis. Leveraging these findings, statistical techniques like discriminant analysis and logistic regression analysis were applied, yielding classification accuracies of 91.7 % and 98.3 %, respectively.

There are no research of how much soil transfer to hand and how long it persists during daily life, although soil is an important trace evidence. Therefore, the transfer and persistence characteristics of soil was investigated. As a result of observing 96 volunteers under the condition of not touching the soil within 1 hour, there was no case that more than grade-1 of soil was detected under the fingernails. 23 of them(24%) exhibited grade-1 of soil. From this point of view, it was found that even if a small amount of soil was attached, it could not be conclusively said that the suspect had recently performed soil-related activities. Also, if a person did not touch the soil, there are no grades higher than 2 were obtained. As a result of observing the transfer and persistence characteristics of soil under fingernails, we found that the soil quickly fell off at the initial stage and then slowly fell over time. In addition, even 120 minutes after touching the soil, 2 of 26 fingers(8%) had grade-3 of soil. So forensic investigators should not give up to collect the soil from suspects, even 120 minutes after arrest. We also found that the act of washing hands affected the amount of soil under the fingernails and the pace of soil persistence. Lastly, we found that the soil more slowly fell off under the fingernail than the fingertip because protection nature of the fingernail.

While delta-8 THC products are used without legal regulation in the United States and other countries, they are legally controlled in South Korea. The types of evidence submitted to the Seoul Institute of National Forensic Service include seized materials, urine, and hair. In this study, we analyzed the results of delta-8 THC-related results from 2021 to June 2023 for seized materials and urine, and from 2022 to June 2023 for hair samples. In total, delta-8 THC was detected in 324 seizures, with the majority of cases (284) containing both delta-8 and delta-9 THC. 33 cases containing delta-8 THC alone, and 7 cases containing delta-8 THC, delta-9 THC, and synthetic cannabinoids. In cases where delta-8 THC was detected alone, the most common evidence type was jelly (14 cases), followed by e-cigarettes. In cases where both components were detected together, e-cigarettes were the most common. There were a total of 83 cases where delta-8 THCCOOH was detected in urine. Among of them, delta-8 THCCOOH was detected alone in 3 cases, while delta-8 THCCOOH and delta-9 THCCOOH were detected together in 75 cases. We analyzed the cases where delta-8 THCCOOH was detected in hair samples. A total of 83 cases were positive, with 16 cases detecting only delta- 8 THCCOOH and 67 cases detecting both delta-8 THCCOOH and delta-9 THCCOOH.