• Title/Summary/Keyword: forensic science

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Research on Effective Scientific Investigation Methods with Regards to Explosion Accidents (폭발사고시 효과적인 과학수사 방법에 관한 연구)

  • Jun, Sang-Gun;Chae, Jong-Min
    • Journal of forensic and investigative science
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    • v.1 no.1
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    • pp.72-87
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    • 2006
  • Accidents and terrorist acts that utilize explosives have a great influence on society and thus require a prompt investigation for the arrest of the culprit. However, such investigations are often met with difficulties due to the vastness of the crime scene, restrictions on approaching the scene, fragility of the evidence, complexity of investigation, and the lack of expertise. In spite of such facts, scientific investigation regarding explosives have not been widely studied in Korea. Therefore, the focus of this research primarily concerns the effective scientific investigation methods in cases of accidents that involve chemical explosives. Although the a systematic investigation method is at the heart of scientific investigation in cases of explosive accidents, it is only at its rudimentary stage. Therefore, in this research, a systematic investigation method is put forth for the 'scene investigation, the documentation of the scene, and the collection and processing of evidence. Further, I have set forth a 'scene investigation check list' the ensure a thorough scene investigation and to promote an exhaustive evidence collection that would guarantee the admissibility of such evidence in court. The above efforts were aimed at simplifying the currently complicated investigation system. 1) In the future, a guidebook that can be generally applied to accidents involving explosives in Korea ught to be produced, a continual systematic education and integrated training excises for investigators ought to be established, laws that require additives in explosives ought to be instituted so that the type, components, and source of explosives can be identified, and lastly, a database that contain information on former explosion accidents, trends, and techniques of criminal activities that involve explosion accidents should be compiled.

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Evaluation of fingerprints enhanced fluorescent using contrast index (Contrast Index를 이용한 형광지문 증강 정도의 수치적 판단)

  • Jeon, Soyoung;Ki, Jinyoung;Kim, Kyuyeon;Kim, Jiyeon;Kim, Chaewon;Yu, Jeseol
    • Analytical Science and Technology
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    • v.31 no.5
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    • pp.195-200
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    • 2018
  • Researchers have used the visual criteria to compare the effectiveness of fingerprint enhancement techniques. However, since the visual criteria is subjective, bias can occur. Therefore, many researchers have tried to make the criteria objective using the contrast index (CI). However, there is a constraint that the CI was only validated on inked fingerprints or color-change fingerprints. In this study, we compared enhancement of fluorescence fingerprints on colored papers using the CI. The CI values differ according to the color of the background, reagent, and light source, even though the same standard fingerprints were used. Through the comparison of values, we could compare the enhancement of fluorescence fingerprints according to these factors. When visual evaluation criteria were used, the same peak score was obtained regardless of the reagent and light source. However, we could get a more detailed score comparison in this study using the CI. Therefore, it is confirmed that for comparison of enhancement of fluorescence fingerprints, the CI can be used as a basis for determining which light source and reagent are appropriate according to the background.

Enhancing CT Image Quality Using Conditional Generative Adversarial Networks for Applying Post-mortem Computed Tomography in Forensic Pathology: A Phantom Study (사후전산화단층촬영의 법의병리학 분야 활용을 위한 조건부 적대적 생성 신경망을 이용한 CT 영상의 해상도 개선: 팬텀 연구)

  • Yebin Yoon;Jinhaeng Heo;Yeji Kim;Hyejin Jo;Yongsu Yoon
    • Journal of radiological science and technology
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    • v.46 no.4
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    • pp.315-323
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    • 2023
  • Post-mortem computed tomography (PMCT) is commonly employed in the field of forensic pathology. PMCT was mainly performed using a whole-body scan with a wide field of view (FOV), which lead to a decrease in spatial resolution due to the increased pixel size. This study aims to evaluate the potential for developing a super-resolution model based on conditional generative adversarial networks (CGAN) to enhance the image quality of CT. 1761 low-resolution images were obtained using a whole-body scan with a wide FOV of the head phantom, and 341 high-resolution images were obtained using the appropriate FOV for the head phantom. Of the 150 paired images in the total dataset, which were divided into training set (96 paired images) and validation set (54 paired images). Data augmentation was perform to improve the effectiveness of training by implementing rotations and flips. To evaluate the performance of the proposed model, we used the Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index Measure (SSIM) and Deep Image Structure and Texture Similarity (DISTS). Obtained the PSNR, SSIM, and DISTS values of the entire image and the Medial orbital wall, the zygomatic arch, and the temporal bone, where fractures often occur during head trauma. The proposed method demonstrated improvements in values of PSNR by 13.14%, SSIM by 13.10% and DISTS by 45.45% when compared to low-resolution images. The image quality of the three areas where fractures commonly occur during head trauma has also improved compared to low-resolution images.

The Influence of Skinning a Carcass on Insect Succession and Decomposition

  • Yoon, Joo-Hyuk
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.3 no.4
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    • pp.204-211
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    • 2022
  • Forensic entomology is a field of study that includes the succession of insects attracted to and found on cadavers. One of its main focusses is estimating post-mortem interval (PMI) based on the growth stage of insects found in and around human cadavers. In many countries, the diversity of insect occurrence is studied in relation to the environmental conditions a cadaver may be exposed to or the effects of different clothes. In this study, changes in the decomposition process and differences in insect succession were investigated by comparing skinned and intact water deer carcasses. Five orders, 15 families, and 21 species of insects were identified, most of which were Dipteran and Coleopteran. The skinned carcass decomposed more rapidly than the intact carcass, which was linked to differences in insect succession. The difference in the decomposition rate and insect succession according to the external conditions of the carcass can be used as basic data for estimating the PMI of the carcass and setting the forensic entomological indicator species.

A study on the false-positive reaction of Kastle-Meyer(KM) test and the application of KM reagent (Kastle-Meyer(KM) test의 위양성 반응과 시약 적용 방법에 관한 연구)

  • Kim, Chae-Lin;Kim, Chang-Yong;Kim, Min-Yeong;Yu, Je-Seol
    • Journal of the Korea Convergence Society
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    • v.11 no.10
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    • pp.139-146
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    • 2020
  • Kastle-Meyer (KM) test is one of presumptive tests used to detect latent blood in crime scenes. While this method is more sensitive than others, false positive reaction can be shown where blood does not exist. In this study, we tried to suggest a new application method to solve this problem. Reaction time and aspect of reaction of this new method was compared with two conventional methods in order to identify the effectiveness and identifiability. As a result, there was no statistically significant difference in sensitivity between the methods. In addition, in case of blood with a dilution ratio of 5000:1 or less, positive reaction showed immediately, making it easy to distinguish the reaction from false positive reaction. However, it became difficult to distinguish them with the reaction time as the dilution ratio increased, and this phenomenon could be supplemented observing aspect of the reaction when using the new method. Therefore, this study suggested a new method for KM test that can be used more accurately in the field.

A study of the distribution of glass particles on patrol car seats (순찰차량 시트에서 유리조각의 분포 연구)

  • Kim, Mihye;Ko, Gangseok;Kim, Sookyung;Hong, Sungwook
    • Analytical Science and Technology
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    • v.29 no.3
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    • pp.136-141
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    • 2016
  • In the present study, the distribution of glass particles inside 10 patrol cars of Chungnam Province has been studied. The target seats were front seats (driver’s seat, passenger’s seat) and the back seat. The target areas were the bottom of the seat (seat contacting buttocks, back of the seat, and the corner of the seat (the bottom and back attached part)). The target areas were tape lifted with an adhesive tape. The glass particles adhering to the adhesive tape were examined and counted under a stereomicroscope. The total number of glass particles found was 679. Among them, 471 (driver’s seat 293, passenger seat 178) were collected from front seats, which are usually occupied by police officers. The majority of glass particles were under 0.49 mm size. The results show that the majority of glass particles can be found on the front seats, rather than on the back seat. There is a high probability that glass particles found on the front seat adhere to police officers, so that to get further transferred to the convict upon physical contact (secondary transfer). Thus, there is a risk of misinterpretation of the value of glass evidence in the course of forensic examinations. Hence, a separate method to prevent cross contamination has to be prepared by police authorities as soon as possible.

Nursing students' experience of visiting the National Institute for Scientific Investigation (간호대학생의 국립과학수사연구소 탐방 경험)

  • Kim, Mi-Hwa
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.3
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    • pp.35-41
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    • 2021
  • The purpose is a qualitative study on the search for career paths of nursing students after visiting the National Institute of Science and Investigation. Participants in this study were 13 people who participated in the National Institute of Science and Investigation visit program during a club event for 3rd graders at a university in M city, Gyeongsangbuk-do. Data collection was made through a self-report within 48 hours of visiting the National Institute of Science and Investigation. The collected data were analyzed using Krippendorff's phenomenological method. As a result of analyzing the experiences of nursing students' visits to the National Institute of Forensic Science, 3 categories, 6 themes, and 20 meaningful statements were identified. The three categories were derived from "Beyond the boundaries of the nursing profession," "The difference between drama and reality", and "Challenge in a new field". As a result of this study, it was confirmed that the experience of visiting the National Institute of Forensic Science provided an understanding of forensic nurses and had opportunities for various social participation attitudes as nurses. In addition, it is expected to be used as basic data useful for career guidance and student counseling in the future, and it is expected to be used as basic data for educational demand structure and educational development for forensic nurses.

Discussion on the Effect of Improving the Image of a Fingerprint Shape Using a Forensic Light Source with Low-pass Filter (Low-pass 필터가 장착된 법과학 광원을 이용한 지문의 형광 이미지 개선 효과에 대한 논의)

  • Lee, A-Ram;Seo, Bo-Gil;Kim, Ju-Bi;Kim, Duke;Yu, Je-Seol
    • The Journal of the Korea Contents Association
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    • v.19 no.12
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    • pp.527-534
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    • 2019
  • Most of the prints left on the crime scene are latent prints. And, even after the latent prints have been developed, additional enhancement is required and forensic light sources are mainly used. Depending on the applied technique and the light source used, it is difficult to obtain the ideal enhancement effect when the reflected light cannot be cut off well. In this study, we improved the wavelength of the forensic light source by attaching a low-pass filter, resulting in better quality fingerprint images.

Optimization of forensic identification through 3-dimensional imaging analysis of labial tooth surface using open-source software

  • Arofi Kurniawan;Aspalilah Alias;Mohd Yusmiaidil Putera Mohd Yusof;Anand Marya
    • Imaging Science in Dentistry
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    • v.54 no.1
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    • pp.63-69
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    • 2024
  • Purpose: The objective of this study was to determine the minimum number of teeth in the anterior dental arch that would yield accurate results for individual identification in forensic contexts. Materials and Methods: The study involved the analysis of 28 sets of 3-dimensional (3D) point cloud data, focused on the labial surface of the anterior teeth. These datasets were superimposed within each group in both genuine and imposter pairs. Group A incorporated data from the right to the left central incisor, group B from the right to the left lateral incisor, and group C from the right to the left canine. A comprehensive analysis was conducted, including the evaluation of root mean square error (RMSE) values and the distances resulting from the superimposition of dental arch segments. All analyses were conducted using CloudCompare version 2.12.4 (Telecom ParisTech and R&D, Kyiv, Ukraine). Results: The distances between genuine pairs in groups A, B, and C displayed an average range of 0.153 to 0.184mm. In contrast, distances for imposter pairs ranged from 0.338 to 0.522 mm. RMSE values for genuine pairs showed an average range of 0.166 to 0.177, whereas those for imposter pairs ranged from 0.424 to 0.638. A statistically significant difference was observed between the distances of genuine and imposter pairs(P<0.05). Conclusion: The exceptional performance observed for the labial surfaces of anterior teeth underscores their potential as a dependable criterion for accurate 3D dental identification. This was achieved by assessing a minimum of 4 teeth.

Forensic STR Analysis of Mixed Chimerism after Allogeneic Bone Marrow Transplantation

  • Eom, Yong-Bin
    • Biomedical Science Letters
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    • v.16 no.3
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    • pp.193-196
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    • 2010
  • Multiplex PCR-based short tandem repeat (STR) analysis is considered as a good tool for monitoring bone marrow engraftment after sex-mismatched allogeneic transplantation and provides a sensitive and accurate assessment of the contribution of both donor and/or recipient cells in post-transplantation specimens. Forensic STR analysis and quantitative real time PCR are used to determine the proportion of donor versus recipient each contained within the total DNA. The STR markers were co-amplified in a single reaction by using commercial $PowerPlex^{(R)}$ 16 system and $AmpFISTR^{(R)}$ $Identifiler^{(R)}$ / $Yfiler^{(R)}$ PCR amplification kits. Separation of the PCR products and fluorescence detection were performed by ABI $PRIS^{(R)}$ 3100 Genetic Analyzer with capillary electrophoresis. The $GeneMapper^{TM}$ ID software were used for size calling and analysis of STR profiles. Extracted DNA was quantified by the $Quantifiler^{TM}$ Human DNA / Y Human Male DNA Quantification Kit The intent of this study was to analyze the ratio of donor versus recipient cells in the post-transplant peripheral blood, spleen, lung and kidney specimens. Specimens were taken from the traffic accident male victim who had been engrafted from bone marrow female donor. Blood and spleen specimens displayed female donor DNA profile. Kidney specimen showed male recipient DNA profile. Interestingly, lung tissue showed mixed profiles. The findings of this study indicate that the forensic STR analysis using fluorescence labeling PCR combined with capillary electrophoresis is quick and reliable enough to assess the ratio of donor versus recipient cells and to monitor the mixed chimeric patterns.