• Title/Summary/Keyword: Forensic Evidence

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A Study on the Role of Computer-Added Stenography in Scientific Investigation (과학적 조사기법에 적합한 컴퓨터 속기의 역할에 관한 연구)

  • Lee, Gyu-An
    • The Journal of the Korea institute of electronic communication sciences
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    • v.6 no.4
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    • pp.533-537
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    • 2011
  • The revision of the criminal procedure act in 2008 marked a great turnaround in the criminal trial system in our country, and the criminal trial system has been based on the trial priority principle from then on. People in general have been entitled to participate in criminal trials, which can be called the jury system, and their awareness of the law has consequently been taken to another level. And the principle of trial by evidence that requires fair process, explanation and scientific evidence is realized in a manner to be appropriate at people(jury)'s level. The prosecution was introduced a video recording system to ensure the efficiency of scientific criminal investigation and assisted every prosecutor's office across the nation to hire computer-added stenographers to back up the documentation of statements during video recording. The purpose of this study was to examine the Korean and foreign computer-added stenography systems and the prospect of computer-added stenography of the video recording system that has been utilized to make a scientific investigation. The effort by this study to look into the roles and prospect of computer-added stenography in the video recording system that has been introduced to improve the efficiency of scientific investigation, which the prosecution pursues, is expected to expedite the advancement of criminal investigation, to guarantee the protection of human rights and to shed new light on the importance and status of computer-added stenography in the trial priority principle.

A Study on the remote acuisition of HejHome Air Cloud artifacts (스마트 홈 헤이 홈 Air의 클라우드 아티팩트 원격 수집 방안 연구)

  • Kim, Ju-eun;Seo, Seung-hee;Cha, Hae-seong;Kim, Yeok;Lee, Chang-hoon
    • Journal of Internet Computing and Services
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    • v.23 no.5
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    • pp.69-78
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    • 2022
  • As the use of Internet of Things (IoT) devices has expanded, digital forensics coverage of the National Police Agency has expanded to smart home areas. Accordingly, most of the existing studies conducted to acquire smart home platform data were mainly conducted to analyze local data of mobile devices and analyze network perspectives. However, meaningful data for evidence analysis is mainly stored on cloud storage on smart home platforms. Therefore, in this paper, we study how to acquire stored in the cloud in a Hey Home Air environment by extracting accessToken of user accounts through a cookie database of browsers such as Microsoft Edge, Google Chrome, Mozilia Firefox, and Opera, which are recorded on a PC when users use the Hey Home app-based "Hey Home Square" service. In this paper, the it was configured with smart temperature and humidity sensors, smart door sensors, and smart motion sensors, and artifacts such as temperature and humidity data by date and place, device list used, and motion detection records were collected. Information such as temperature and humidity at the time of the incident can be seen from the results of the artifact analysis and can be used in the forensic investigation process. In addition, the cloud data acquisition method using OpenAPI proposed in this paper excludes the possibility of modulation during the data collection process and uses the API method, so it follows the principle of integrity and reproducibility, which are the principles of digital forensics.

The Effect of Investigators' Perception of the Importance of Investigative Elements on Their Intention to Use Profiling: Mediating Effect of Attitude toward Profiling (수사관의 수사요소 중요도 인식이 프로파일링 활용 의도에 미치는 영향: 프로파일링에 대한 태도의 매개효과)

  • Shin, Sangwha;Yoon, Sangyeon
    • Korean Journal of Forensic Psychology
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    • v.13 no.1
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    • pp.75-97
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    • 2022
  • Profiling is recognized as a representative application area of domestic criminal psychology, and the National Police Agency profiler is firmly established as a profession. However, compared to the social awareness, the recognition and utilization within the police is not high. In this study, we tried to identify factors affecting the intention to use profiling by identifying the perception of investigators who request and use profiling from a profiler when a violent incident occurs. To this end, the relationship between the perception of the importance of factors considered by investigators in the criminal investigation process and the attitude toward profiling on the intention to use profiling was verified through the path model. As a result of a survey of 340 police investigators, the investigator's perception of the importance of investigation elements was divided into two factors: the importance of normative investigative elements (evidence collection and legal judgment, etc.) and factual investigative elements (criminal analysis, criminal information system analysis, etc.). Among them, the importance of factual investigative elements were found to have a positive effect on the intention to use it by mediating the attitude toward profiling. On the other hand, in the case of the importance of normative investigative elements, it was found to have a negative effect on the attitude toward profiling. These results suggest that the perception that investigators have about investigation, which is their main work area, plays a role in determining whether to request profiling as well as attitude towards profiling. Based on the research results, strategies necessary to activate the use of profiling were discussed.

A Design of Timestamp Manipulation Detection Method using Storage Performance in NTFS (NTFS에서 저장장치 성능을 활용한 타임스탬프 변조 탐지 기법 설계)

  • Jong-Hwa Song;Hyun-Seob Lee
    • Journal of Internet of Things and Convergence
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    • v.9 no.6
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    • pp.23-28
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    • 2023
  • Windows operating system generates various logs with timestamps. Timestamp tampering is an act of anti-forensics in which a suspect manipulates the timestamps of data related to a crime to conceal traces, making it difficult for analysts to reconstruct the situation of the incident. This can delay investigations or lead to the failure of obtaining crucial digital evidence. Therefore, various techniques have been developed to detect timestamp tampering. However, there is a limitation in detection if a suspect is aware of timestamp patterns and manipulates timestamps skillfully or alters system artifacts used in timestamp tampering detection. In this paper, a method is designed to detect changes in timestamps, even if a suspect alters the timestamp of a file on a storage device, it is challenging to do so with precision beyond millisecond order. In the proposed detection method, the first step involves verifying the timestamp of a file suspected of tampering to determine its write time. Subsequently, the confirmed time is compared with the file size recorded within that time, taking into consideration the performance of the storage device. Finally, the total capacity of files written at a specific time is calculated, and this is compared with the maximum input and output performance of the storage device to detect any potential file tampering.

Microbial Forensics: Comparison of MLVA Results According to NGS Methods, and Forensic DNA Analysis Using MLVA (미생물법의학: 차세대염기서열분석 방법에 따른 MLVA 결과 비교 및 이를 활용한 DNA 감식)

  • Hyeongseok Yun;Seungho Lee;Seunghyun Lim;Daesang Lee;Sehun Gu;Jungeun Kim;Juhwan Jeong;Seongjoo Kim;Gyeunghaeng Hur;Donghyun Song
    • Journal of the Korea Institute of Military Science and Technology
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    • v.27 no.4
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    • pp.507-515
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    • 2024
  • Microbial forensics is a scientific discipline for analyzing evidence related to biological crimes by identifying the origin of microorganisms. Multiple locus variable number tandem repeat analysis(MLVA) is one of the microbiological analysis methods used to specify subtypes within a species based on the number of tandem repeat in the genome, and advances in next generation sequencing(NGS) technology have enabled in silico anlysis of full-length whole genome sequences. In this paper, we analyzed unknown samples provided by Robert Koch Institute(RKI) through The United Nations Secretary-General's Mechanism(UNSGM)'s external quality assessment exercise(EQAE) project, which we officially participated in 2023. We confirmed that the 3 unknown samples were B. anthracis through nucleic acid isolation and genetic sequence analysis studies. MLVA results on 32 loci of B. anthracis were analysed by using genome sequences obtained from NGS(NextSeq and MinION) and Sanger sequencing. The MLVA typing using short-reads based NGS platform(NextSeq) showed a high probability of causing assembly error when a size of the tandem repeats was grater than 200 bp, while long-reads based NGS platform(MinION) showed higher accuracy than NextSeq, although insertion and deletion was observed. We also showed hybrid assembly can correct most indel error caused by MinION. Based on the MLVA results, genetic identification was performed compared to the 2,975 published MLVA databases of B. anthracis, and MLVA results of 10 strains were identical with 3 unkonwn samples. As a result of whole genome alignment of the 10 strains and 3 unknown samples, all samples were identified as B. anthracis strain A4564 which is associated with injectional anthrax isolates in heroin users.

Quality Characteristics of Coffee Brewed from Green Beans Soaked in Mulberry (Morus bombycis) Extract (오디(Morus bombycis) 추출물 침지 커피의 품질 특성)

  • Lim, Hyun Hwa;Ji, Seokgeun;Kwak, Han Sub;Eom, Taekil;Kim, Misook;Lee, Youngseung;Do, Jae Wook;Yu, Sungryul;Choi, Geun Pyo;Jeong, Jin Il;Jeong, Yoonhwa
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.4
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    • pp.579-585
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    • 2015
  • The objective of this study was to investigate the quality characteristics of coffee soaked in Morus bombycis extract. Green coffee beans were soaked in M. bombycis extract for 2, 4, and 6 hours (sample codes: 2H, 4H, and 6H) at $4^{\circ}C$. Soaked green beans were dried and roasted for coffee extraction. Two controls, roasted with the same amount of heat (C1) and showed the same weight after roasting (C2), were used. Physicochemical characteristics (pH, total acidity, color, browning index, and total soluble solids), DPPH free radical scavenging activity (DPPH), ferric-reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), total polyphenol content (TPC), and total flavonoid content (TFC) were investigated. Lower pH and higher total acidity were observed in 2H, 4H, and 6H (P<0.05), supporting evidence of sour taste. There were significant differences in DPPH between the controls (45.51~47.02%) and samples (50.67~55.25%, P<0.05), although 2H and 6H did not show significantly higher DPPH than the controls. 2H, 4H, and 6H showed significantly higher FRAP values ($0.320{\sim}0.331\;FeSO_4{\cdot}7H_2O\;mM\;FeSO_4/g$) than controls ($0.265{\sim}0.271\;mM\;FeSO_4/g$). ORAC values of samples [1,062.86~1,153.68 mM trolox equivalent (TE)/g] were significantly higher than those of controls (689.40~942.12 mM TE/g). 2H, 4H, and 6H showed significantly higher TPC [24.27~26.07 mg gallic acid equivalent (GAE)/g] and TFC [3.75~4.28 mg quercetin equivalent (QE)/g] than controls (19.79~22.77 mg GAE/g and 1.07~1.95 mg QE/g, respectively) (P<0.05). M. bombycis extracts soaked into green coffee beans showed polyphenol compounds from green coffee beans. Consumer acceptance of 4H (5.12) was the highest, followed by C2 (4.92). C1 (4.14) showed the lowest consumer acceptance. Consumers were segmented into two groups, those who preferred M. bombycis extract-soaked coffee (approximately 61%) and controls (approximately 39%).

The verdict category and legal decision: Focused on the role of representation of 'innocent' (평결범주와 일반인의 법적판단: '무죄표상'의 역할을 중심으로)

  • Han, Yuhwa
    • Korean Journal of Forensic Psychology
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    • v.13 no.1
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    • pp.1-22
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    • 2022
  • This study tested the effect of the verdict category of lay-participation trial in Korea on the legal decision of layperson and the role of representation of 'innocent' in the process. Representation of 'innocent' refers to a psychological threshold for deciding someone's innocence (no fault or sin) in a general sense. The functions as a threshold for a legal decision of 'beyond a reasonable doubt (BRD)' and the individual threshold (IT), regarded as a standard for judgment of guilt established by law and an estimate of an individual's threshold, respectively, were compared. This study used a 2×2 complete factorial design in which the verdict category (guilty/innocent vs. guilty/not guilty) and the defendant's likelihood of guilt (low vs. high) were manipulated. Data from 137 lay-people who voluntarily participated in the online experiment was analyzed. The experiment's procedure was in the order of measuring 'representation of innocent' and the likelihood of guilt of an accused, presenting one of four trial vignettes, and obtaining legal decisions (verdict confidence and estimation of the likelihood of guilt for the defendant). As a result, it was found that the verdict category did not significantly affect the legal decision of layperson. However, the guilty verdict rate of the 'guilty/innocent' condition tended to be higher than those of the 'guilty/not guilty' condition. The layperson's representation of 'innocent' and the verdict category had an interaction effect on the difference between BRD and IT (threshold change) at the significance level of .1. In the 'guilty/innocent' condition, the threshold change varying with layperson's representation of 'innocent' was larger than in the 'guilty/not guilty' condition. In comparing the function of BRD and IT, IT significantly predicted the lay person's legal decision at the significance level of .1 by interacting with the likelihood of guilt for the defendant. Therefore, it could be said that IT was a better threshold estimator than BRD. The implication of this study is that it provided experimental evidence for the effect of the verdict category of lay-participation trial in Korea, which is a problem often raised among lawyers, and suggested logical reasoning and empirical grounds for the psychological mechanism of the possible effect.

An exploration of the relationship between crime/victim characteristics and the victim's criminal damages: Variable selection based on random forest algorithm (범죄 및 피해자 특성과 범죄피해 내용의 관계 탐색: 랜덤포레스트 알고리즘에 기초한 변인선택)

  • Han, Yuhwa;Lee, Wooyeol
    • Korean Journal of Forensic Psychology
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    • v.13 no.2
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    • pp.121-145
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    • 2022
  • The current study applied the random forest algorithm to Korean crime victim survey data collected biennially between 2010 and 2018 to explore the relationship between crime/victim characteristics and the victim's criminal damages. A total of 3,080 cases including gender, age (life cycle stage), type of crime, perpetrator acquisition, repeated victimization, psychological damage (depression, isolation, extreme fear, somatic symptoms, interpersonal problems, moving out to avoid people, suicidal impulses, suicide attempts), and emotional changes after victimization (changes in self-protection confidence, self-esteem, confidence in others, confidence in legal institutions, and respect for Korean legal system/law) were analyzed. Considering the features of data that are difficult to apply traditional statistical techniques, this study implemented random forest algorithms to predict crime and victim characteristics using the victim's criminal damages (psychological damage and emotional change) and selected good predictors using VSURF function in VSURF package for R. As a result of the analysis, it was confirmed that the relationship between the type of crime and depression, extreme fear, somatic symptoms, and interpersonal problems, between perpetrator acquisition and somatic symptoms and interpersonal problems, and between repeated victimization and changes in respect for Korean legal system/law. Gender and life cycle stage (youth/adult/elderly) were found to be related to extreme fear and changes in self-protection confidence, respectively. However, more empirical evidence should be aggregated to explain the results as meaningful. The results of this study suggest that it is necessary to enhance the experts' knowledge and educate them on cases about the relationship between crime/victim characteristics and criminal damage. Strengthening their interview strategy and knowledge about law/rules were also needed to increase the effectiveness of the Korean victim assessment system.