• Title/Summary/Keyword: forensic science

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Microbial Forensics: Human Identification

  • Eom, Yong-Bin
    • Biomedical Science Letters
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    • v.24 no.4
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    • pp.292-304
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    • 2018
  • Microbes is becoming increasingly forensic possibility as a consequence of advances in massive parallel sequencing (MPS) and bioinformatics. Human DNA typing is the best identifier, but it is not always possible to extract a full DNA profile namely its degradation and low copy number, and it may have limitations for identical twins. To overcome these unsatisfactory limitations, forensic potential for bacteria found in evidence could be used to differentiate individuals. Prokaryotic cells have a cell wall that better protects the bacterial nucleoid compared to the cell membrane of eukaryotic cells. Humans have an extremely diverse microbiome that may prove useful in determining human identity and may even be possible to link the microbes to the person responsible for them. Microbial composition within the human microbiome varies across individuals. Therefore, MPS of human microbiome could be used to identify biological samples from the different individuals, specifically for twins and other cases where standard DNA typing doses not provide satisfactory results due to degradation of human DNA. Microbial forensics is a new discipline combining forensic science and microbiology, which can not to replace current STR analysis methods used for human identification but to be complementary. Among the fields of microbial forensics, this paper will briefly describe information on the current status of microbiome research such as metagenomic code, salivary microbiome, pubic hair microbiome, microbes as indicators of body fluids, soils microbes as forensic indicator, and review microbial forensics as the feasibility of microbiome-based human identification.

Cold Boot Attack on Encrypted Containers for Forensic Investigations

  • Twum, Frimpong;Lagoh, Emmanuel Mawuli;Missah, Yaw;Ussiph, Najim;Ahene, Emmanuel
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.9
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    • pp.3068-3086
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    • 2022
  • Digital Forensics is gaining popularity in adjudication of criminal cases as use of electronic gadgets in committing crime has risen. Traditional approach to collecting digital evidence falls short when the disk is encrypted. Encryption keys are often stored in RAM when computer is running. An approach to acquire forensic data from RAM when the computer is shut down is proposed. The approach requires that the investigator immediately cools the RAM and transplant it into a host computer provisioned with a tool developed based on cold boot concept to acquire the RAM image. Observation of data obtained from the acquired image compared to the data loaded into memory shows the RAM chips exhibit some level of remanence which allows their content to persist after shutdown which is contrary to accepted knowledge that RAM loses its content immediately there is power cut. Results from experimental setups conducted with three different RAM chips labeled System A, B and C showed at a reduced temperature of -25C, the content suffered decay of 2.125% in 240 seconds, 0.975% in 120 seconds and 1.225% in 300 seconds respectively. Whereas at operating temperature of 25℃, there was decay of 82.33% in 60 seconds, 80.31% in 60 seconds and 95.27% in 120 seconds respectively. The content of RAM suffered significant decay within two minutes without power supply at operating temperature while at a reduced temperature less than 5% decay was observed. The findings show data can be recovered for forensic evidence even if the culprit shuts down the computer.

Analysis on the Fire Accidents Vehicles Caused by Faults in the Same Anti-lock Brake System (ABS) of the same Manufacturer (동일한 제조사의 ABS 모듈 결함으로 인한 차량화재 사고사례 분석)

  • Park, Nam-Kyu;Lee, Dong-Kyu;Cho, Young-Jin;Moon, Byung-Sun;Song, Jae-Yong
    • Fire Science and Engineering
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    • v.33 no.3
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    • pp.121-127
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    • 2019
  • This study examined a fire accident caused by a defect in the vehicle ABS module. A large number of vehicles using the same manufacturer's ABS module in recent fire events showed a tendency to combust due to the same faults. As previously stated in the ABS module which shows the electrical breakdown between the power lines supplied to the constant power source by the battery. The electrical breakdown of the ABS module was caused by defects of the ABS module itself that were influenced by of the external flame. These results highlight the need to determine if there is a deficiency of the ABS module in the investigation of the cause of a fire in a vehicle which is produced by the same manufacturer.

Analysis on Vehicle Fires Caused by Damage of Diesel Particulate Filter (DPF) (매연저감장치 손상에 기인한 차량화재 사고사례 분석)

  • Song, Jae-Yong;Sa, Seung-Hun;Nam, Jung-Woo;Cho, Young-Jin;Kim, Jin-Pyo;Park, Nam-Kyu
    • Fire Science and Engineering
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    • v.26 no.4
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    • pp.70-76
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    • 2012
  • This paper deal with vehicle fire caused by damage of diesel particulate filter (DPF) on diesel passenger vehicles. In order to reduce particulate matters included exhaust gases, a DPF in the exhaust system were installed diesel vehicles. A DPF was broken by excessively trapped particulate matters, regeneration error with a malfunction of ECU and defect of suction system such as swirl valve. If the DPF was broken, hot exhaust gases was released to the bottom of vehicle and released hot exhaust gases lead to occur the fire through combustible materials around the exhaust system. When a fire happened in the diesel vehicle caused by damage of DPF, silicate inorganic compounds were attached to the exhaust ventilation pipe and muffler. The silicate inorganic compounds were created by DPF combustion consisting of raw material ceramics. If the silicate inorganic compounds attached to the tail pipe in the diesel passenger vehicles, its fire cause will be assumed damage of DPF.

Detection of Innate and Artificial Mitochondrial DNA Heteroplasmy by Massively Parallel Sequencing: Considerations for Analysis

  • Kim, Moon-Young;Cho, Sohee;Lee, Ji Hyun;Seo, Hee Jin;Lee, Soong Deok
    • Journal of Korean Medical Science
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    • v.33 no.52
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    • pp.337.1-337.14
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    • 2018
  • Background: Mitochondrial heteroplasmy, the co-existence of different mitochondrial polymorphisms within an individual, has various forensic and clinical implications. But there is still no guideline on the application of massively parallel sequencing (MPS) in heteroplasmy detection. We present here some critical issues that should be considered in heteroplasmy studies using MPS. Methods: Among five samples with known innate heteroplasmies, two pairs of mixture were generated for artificial heteroplasmies with target minor allele frequencies (MAFs) ranging from 50% to 1%. Each sample was amplified by two-amplicon method and sequenced by Ion Torrent system. The outcomes of two different analysis tools, Torrent Suite Variant Caller (TVC) and mtDNA-Server (mDS), were compared. Results: All the innate heteroplasmies were detected correctly by both analysis tools. Average MAFs of artificial heteroplasmies correlated well to the target values. The detection rates were almost 90% for high-level heteroplasmies, but decreased for low-level heteroplasmies. TVC generally showed lower detection rates than mDS, which seems to be due to their own computation algorithms which drop out some reference-dominant heteroplasmies. Meanwhile, mDS reported several unintended low-level heteroplasmies which were suggested as nuclear mitochondrial DNA sequences. The average coverage depth of each sample placed on the same chip showed considerable variation. The increase of coverage depth had no effect on the detection rates. Conclusion: In addition to the general accuracy of the MPS application on detecting heteroplasmy, our study indicates that the understanding of the nature of mitochondrial DNA and analysis algorithm would be crucial for appropriate interpretation of MPS results.

Forensic analysis of toxic substances in fatalities with suspected companion animal cruelty (반려동물 학대 의심 폐사축에 대한 중독물질검사 연구)

  • JeongWoo Kang;Ah-Young Kim;Hyun Young Chae;Hanae Lim;Suncheun Kim;Bok-Kyung Ku;Kyunghyun Lee
    • Korean Journal of Veterinary Research
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    • v.63 no.3
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    • pp.21.1-21.6
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    • 2023
  • The increasing prevalence of toxic substance-exposure in pets in South Korea endangers the health and safety of numerous companion animals, and has become a cause for concern. Notably, the annual incidence of forensic analysis in pets has increased by more than 150% in South Korea, mainly in populous regions such as Seoul, Incheon, and Gyeonggi. In response to this growing issue, veterinary forensic examinations were conducted on 549 dogs and cats from 2019 to 2022. This study revealed the presence of various toxic substances, including pesticides, insecticides, and drugs such as analgesics, anesthetics, antidepressants, and muscle relaxants, in pets. Among the 38 different toxins identified in pets, coumatetralyl, methomyl, terbufos, and buprofezin were the most frequently detected. In this study, toxic substances for pets were identified based on the "toxic agent list for humans," developed by the National Forensic Services, because no list of toxic agents for animals currently exists and data regarding potentially toxic substances for dogs and cats is limited. This is one of the limitations of this study, and necessitates the establishment of a toxic agent list for animals. Continued monitoring and research is also recommended to reveal the incidence, causes, and solutions of toxicity in animals.

Inappropriateness in Completing a Death Certificate (사망진단서 작성에 있어서 부적절성)

  • Lee, Hyun-Ji;Lee, Sang-Han
    • Journal of forensic and investigative science
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    • v.3 no.1
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    • pp.43-49
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    • 2008
  • This study was conducted to analyze the current problems in completing death certificates and to identify the correct method for completing death certificates. Total 298 death certificates in A hospital from January to December in 2005 were reviewed. There was only 88 death certificates (29.5%) without an error. The frequency of the major errors were 8.7% in 'mechanism of death listed instead of cause of death', 9.4% in 'competing causes', and 11.4% in 'improper sequencing'. The frequency of minor errors were 99.3% in 'absence of time intervals', 19.5% in 'repetition of same cause', 18.8% in "more than 2 causes listed in same space". Errors were common in the completion of death certificates in the middle sized hospital setting. It is very important to complete death certificate accurately in practice. Education in undergraduate course and persistent training in internship and residency program will be needed.

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The shelf life of 1,2-indandione/zinc and polyvinylpyrrolidone solutions used to develop latent fingermarks deposited on the surface of thermal paper (감열지에 부착된 잠재지문을 현출하는데 사용하는 1,2-indandione/zinc와 polyvinylpyrrolidone 용액의 보존기한)

  • Hong, Sungwook;Kim, Yujin;Kim, Hyunjung;Kim, Hyerim;Lee, Junchul;Yu, Seoungho
    • Analytical Science and Technology
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    • v.30 no.6
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    • pp.312-318
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    • 2017
  • The shelf life of 1,2-indandione/zinc (1,2-IND/Zn) solution and polyvinylpyrrolidone (PVP) solution, which are known as reagents for developing latent fingermarks deposited on the surface of thermal paper, was studied. The standard latent fingermarks used for comparisons were artificial latent fingermarks printed on thermally sensitive and non-sensitive surfaces with the same intensity. Upon treatment of standard latent fingermarks with the pre-mixed 1,2-IND/Zn and PVP solutions, the fingermarks could be successfully developed until 3 days after the preparation of the mixture. However, from the third day after mixing the reagents, blackening was observed on the surface of the thermal paper, indicating deterioration of the reagent performance. The 1,2-IND/Zn and PVP solutions separately stored without mixing in advance were mixed immediately before use, and the development efficiency of the latent fingermarks deposited on the surface of thermal paper was observed. The performance of the PVP solution decreased after 20 days from the preparation of the reagent. It was also found that the shelf life of 1,2-IND/Zn and PVP mixture was determined by the PVP solution. The effect of oxygen and moisture on the degradation of PVP was investigated. It was found that the performance of the PVP solution deteriorated because of the influence of moisture, though it was not affected by oxygen.

The Availability of Forensic Accounting Application Factors to Enhance the Auditors Efficiency in Jordan

  • ABU-TAPANJEH, Abdussalam Mahmoud;AL-SARAIRAH, Tasnim Muhammad Khalaf
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.807-819
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    • 2021
  • This study aims to determine the availability of forensic accounting application factors sought by auditors' representatives of Jordanian Certified Public Accounting and auditors working in the Audit Bureau. The study identifies as well the role of these application factors in enhancing the efficiency of auditors due to the increased responsibility on them in the face of various fraud cases on the one hand, and their appearance in the courts as financial experts supporting the judiciary to adjudicate financial cases on the other hand. To achieve the objectives of the study, the researchers used the descriptive analytical method because of its suitability for the nature of the research. The population of the study consisted of 433 Jordanian certified public accountants and 520 auditors working in the Audit Bureau, from which a sample of 426 was constructed. A questionnaire was developed to collect data and the Statistical Package for Social Sciences was utilized to analyze data and test hypotheses. The study found that there is a statistical difference between the responses of the two samples of the study, and it concluded a set of recommendations, which are hoped to help legislators in strengthening and developing the forensic accounting profession in Jordan.

Preliminary study for aging of latent fingerprints on nonporous substrate

  • Nam Yee Kim;Woo-Yong ParK;Jong Shin Park;Yuna Kim;Hee Sook Kim
    • Analytical Science and Technology
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    • v.36 no.2
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    • pp.80-88
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    • 2023
  • Fingerprints play a crucial role in the identification of potential suspects in criminal cases. However, determining the actual time, i.e., the time at which the fingermark was deposited, is challenging. Herein, we investigated the persistence and aging of fingerprints over time by observing the time evolution of latent fingerprints on a polystyrene box stored in a dark room. Fingerprint samples that were stored for up to two years could be detected with maximum accuracy using a black iron-oxide-based emulsion (black emulsion). To estimate the time of fingerprint deposition, fingerprint aging was studied by analyzing the lipid components of the fingerprints after their development. Cholesterol and squalene were selected as indicators of fingerprint aging, and their ratio was estimated to assess aging. In the case of fingerprint samples stored in a dark room for up to one month after deposition, the cholesterol/squalene ratio was approximately 0.01; it increased gradually to ≥ 0.1 over six months. A substantial reduction in the levels of cholesterol and squalene from the initial levels was also noted. Cholesterol and squalene were not detected after one year of storage. Thus, the extent of aging could be determined by analyzing the aging indicators for up to six months. Two cases that could cause error in the estimation of the fingerprint deposition time, namely, heating of the fingerprint sample before development and storage of the developed fingerprints in a dark room, were also investigated.