共查询到20条相似文献，搜索用时 15 毫秒
1.
2.
《Science & justice》2021,61(4):419-425
Evaluation of forensic evidence using Bayesian statistics requires the formulation of hypotheses. Many hypotheses, especially those presenting the defence viewpoint imply that traces can be attributed to an arbitrary member of a relevant population. The exact items or persons that comprise the relevant population may vary from case to case. Therefore, the statistical evaluation of evidential value based on databases cannot make use of a fixed set of items or persons. In the current paper, methodology is presented to filter the contents of a database such that only items that are considered relevant are selected. Six scenarios, including those related to fibre, textile, and glass evidence are described, together with the hypotheses and relevant populations that may be evaluated by an expert. In addition, we show how items representing the defined relevant population can be extracted from a database using SQL code. Images of the items in the (filtered) relevant population provide an overview of the selected items and hence direct feedback to the examiner. In this way, erroneous codes or unwanted side effects can be identified and corrected. It is concluded that the filtering procedure is effective in cases where the relevant population is demarcated accurately. 相似文献
3.
本文根据近年来国外法庭微量物证检验方面的研究成果,从检验对象、检验技术及发展趋势三个方面总结了当前国外微量物证的研究现状。介绍了近年来国外法庭科学家在常见的微量物证如油漆、纤维、玻璃等的检测方法和检测技术,尤其重点介绍了一些新技术如电感耦合等离子体原子发射光谱技术(ICP/AES)、微波辅助消融和等离子光谱技术(OES/ICP)、激光等离子质谱联用技术(LA/ICP/MS)等在微量物证中的应用。指出国外微量物证研究相对于国内微量物证研究在技术应用、数据库建立、数据分析、合作研究等方面的优越性。 相似文献
4.
《Science & justice》2020,60(6):512-521
Footwear marks are one of the most frequently encountered evidence types recovered from a crime scene and can provide valuable scene intelligence regarding potential suspects. It has been acknowledged that impressions of footwear and tools can be recovered from graves, but previous studies have only focused on tool mark recovery. This has led to a lack of published information regarding footwear mark recovery from graves. It is therefore important to demonstrate whether the recovery of footwear marks is feasible and, if so, under what conditions this can be achieved. To address recovery, this study, placed 60 three dimensional (3D) impressions of footwear marks within 60 simulated graves. This was done to assess time (1, 2, 4 months) and at known depths (20, 30, 40 cm). The footwear marks within the graves were covered with clothing or left uncovered. The shoe’s design patterns were grouped and counted in a photographic comparison between the 3D footwear impressions, placed within the test-pits, and any recovered impressions. A grading system was adapted by the authors to score the quality of footwear impressions observed during recovery. The results demonstrate that the preservation and recovery of footwear impressions from graves is feasible. The simulated graves covered with clothing showed better preservation of footwear impressions, but there was no clear evidence that time or depth had an effect. The authors note that careful consideration and vigilant excavation skills are needed when excavating graves which may bear potential footwear marks, as their recovery will lead to an increased amount of intelligence that can link suspects to homicide scenes. 相似文献
5.
《Science & justice》2020,60(6):531-537
Forensic scientists must be able to recover traces of any original explosive materials not consumed in the detonation, in a careful controlled manner to aid a crime reconstruction. In current sampling techniques, the collection efficiency of post-blast residue is highly variable and often dependent on the swabbing materials and solvent systems used. To address these method limitations, this study presents a gelatine-based sampling medium and assesses its capabilities for the collection of ammonium nitrate. Common surfaces were spotted with a known concentration of ammonium nitrate, the unset gel applied, allowed to set, and then peeled from the surface. The gel was dissolved, and solid phase extraction employed to isolate the target explosive compound and remove the constituents of the gel. The eluate was concentrated and subsequently analysed and quantified. Overall, the gel formulation was able to collect ammonium nitrate from all of the test surfaces, with recoveries ranging from 0.1% to 61.7%. This study presents a gelatine-based formulation that has the potential to become a valuable asset in the forensic tool kit for the collection of explosive traces. A key attribute of the gel is that it offers an alternative recovery tool to conventional swabbing and solvent extraction methods. 相似文献
6.
《Science & justice》2022,62(3):327-335
Cosmetic smears are a form of trace evidence that can link the crime scene, suspects, and victims. Foundation and lipstick are the most common sources of cosmetics that can easily smear, with most current research focused on the evidential analysis of lipsticks. This research aims to create a database of cosmetic foundations on different materials and to access the robustness of using Near-infrared with chemometrics as a non-destructive technique to identify unknown samples collected from a crime scene. Small amounts of six shades of three brands of foundations were smeared on clothing materials, which were then analysed with a combination of Near-infrared with chemometric analysis. Principle component analysis (PCA) was used to reduce data dimensionality and explore potential patterns in sample separation and Linear Discriminant Analysis (LDA) was utilised to assign unknown samples to one of the established classes. The selected techniques proved to be promising for database construction and as a preliminary method of analysis, with 93% of the spectra being correctly classified. Notably, darker foundation shades were less likely to be correctly classified (90% classified correctly) compared to lighter ones (96.7% classified correctly). This could not be improved with Standard Normal Variate (SNV) data pre-treatment or selecting specific NIR regions. This finding is of particular importance; according to the Crime Survey for England and Wales (year ending March 2020) police recorded sexual offences demonstrated that those in Mixed and Black or Black British ethnic groups were significantly more likely to be a victim of sexual assault compared to White, Asian or Other ethnic groups. It is, therefore, crucial to add a wide range of foundation shades, particularly of darker tones, to the future database. 相似文献
7.
《Science & justice》2023,63(3):376-386
Environmental trace evidence offers useful circumstantial intelligence to link persons and scenes of forensic interest. An increasing empirical research base is dedicated towards understanding the transfer and persistence dynamics of environmental indicators including pollen, soils, and diatoms, within a diverse range of experimental frameworks. This paper presents two discrete studies exploring transfer and persistence of soils and sediments on footwear and diatomaceous earth adhered to clothing in forensically pertinent scenarios. Variables including sediment type, foot position, clothing type, and body positioning were also explored throughout. Both experiments incorporated a field-based methodology during the sampling effort. Photographs were collected of an initial transfer sample and of a retained assemblage following hours, days, and up to one-week of wear, facilitating macroscopic assessment of trace evidence dynamics. All images were processed using accessible, open-source software before spatial analysis of evidence distribution within and temporal assessment (% retention) upon each evidential surface. The results highlighted consistent loss of transferred sediment from footwear with significantly greater retention of loamy clay soil than dune sand which was absent beyond 24 h of wear. Loss was not influenced by wearer gait but was more rapid from those areas of the shoe sole in direct contact with the ground. Diatomaceous earth was retrieved from all three clothing types tested after one week – significant losses of material occurred before 48 h with a consistent assemblage identified beyond this. Denim was significantly more effective than acrylic and fleece for diatomaceous earth retention and significantly more material was lost from clothing worn on the lower body. These findings highlight the value of using visual environmental markers and a macroscopic analytical approach during the investigation of environmental trace dynamics. The methodology offers a novel, non-destructive assessment of soil and diatom transfer and persistence, complementing more extensive laboratory-based examinations to ensure the development of a well-rounded research base within the forensic sciences. 相似文献
8.
With the increase in sensitivity of DNA profiling, questions about how and when the DNA was deposited have become a driving issue in forensic cases. To address this, we propose a novel method to determine time since deposition of trace DNA samples based on morphological and autofluorescence properties of individual epithelial cells which can change as the sample ages. To develop this signature, a series of trace DNA samples were generated by contact/handling a substrate and then allowed to age anywhere between one day and more than one year prior to collection. Imaging flow cytometry (IFC) was then used to characterize the morphology and autofluorescence profiles of individual cells within each sample followed by multivariate modelling and predictive classification.Resultsshowed that epithelial cell populations could be classified with high accuracy (∼90%) into one of three time-since-deposition groups: < 1 week, between 1 week and 2 months, and > 2months. Differences across age groups were largely driven by decreases in brightfield contrast and increases in the intensity of autofluorescence. To further test this approach for forensic casework, 47 individual donor cell populations spanning each time deposition group were classified blindly against the remaining data set. Samples containing at least 75 cells and a posterior probability greater than 0.90 showed classification accuracies ∼95%. Accuracies for individual time groups were 97% (<1 week), 92% (1week-2months), 98% (>2 months) with an average posterior probability for all time groups ∼0.96. This indicates that autofluorescence and morphological analyses may provide probative information regarding time since deposition for many types of trace DNA samples in forensic casework. 相似文献
9.
目的探讨改良扩增前引物延伸(IPEP)法对痕量DNA样本STR检测分型的效果。方法用改良IPEP法对痕量样品DNA进行全基因组扩增(WGA),扩增产物用实时荧光定量PCR技术定量、用AmpFLSTR~ Indentifiler~试剂盒作基因型检测。结果该方法可增加模板DNA约200~1100倍。基因组DNA不低于0.025ng时,可获得15个STR基因座和Amelogenin性别基因座的分型结果。基因组DNA0.01~0.025ng时,可获得9个以上基因座的分型结果。结论改良IPEP法可有效提高痕量DNA样本STR分型检验的灵敏度,有较好的实用价值。 相似文献
10.
目的建立一种对单核苷酸多态性(SNPs)位点进行复合检测的方法,并对人类DRB基因的单核苷酸多态性进行研究。方法 应用荧光标记双脱氧核苷酸进行单碱基延伸反应,同步检测人类DRB基因10个单核苷酸多态性位点。结果 应用该方法检验了人类标准细胞株K562、9947A及其他法医学常见生物检材,包括血斑2份、精斑5份、烟蒂8份、毛发3份,各样品间未发现相同的单核苷酸多态性组合单倍型。DNA模板需要量仅为0.5~1.0ng。结论 该方法是对微量生物物证进行个体识别鉴定的理想方法。同时还可为法医学及其他研究领域进行单核苷酸多态性分析提供快速、高效的技术手段。 相似文献
11.
12.
《Science & justice》2020,60(1):53-62
It has recently been established that volatile organic compounds (VOCs) successfully transfer between clothing even with a short contact of 10 s, highlighting the potential to use VOCs in forensic reconstruction scenarios, such as sexual assault cases. The mid and low volatility compounds transferred in greater amounts than high volatility compounds. This study presents empirical data addressing the persistence of transferred VOCs on clothing for the first time. A series of experiments were carried out to determine the persistence of VOCs on clothing for time periods of up 4 weeks, on natural and synthetic fibres, and at three different environmental temperatures. The data indicate that the highest VOC amounts are generally obtained for shorter persistence times of up to 1 d. Whilst high volatility compounds were not recovered in sufficient amounts to allow quantification, the four other transferred VOCs were successfully quantified for persistence times of up to 4 weeks. The persistence for mid-volatility compounds follows decay curve trends in line with those previously obtained for fibres, glass and pollen. When comparing the persistence of VOCs on a natural and a synthetic fibre, for a persistence time of 1 h, the transferred VOCs were retained on a natural fibre in higher amounts than on a synthetic fibre. However, for longer persistence times the concentration of VOCs was similar between the two fabrics. Lastly, lower environmental temperatures resulted in higher recoveries for most VOCs, especially for short persistence times. These findings demonstrate that optimal recovery of VOCs from clothing occurs when the fabric is kept at cooler temperatures and analysed soon after the fragrance transfer occurred, although VOC recovery was possible at higher temperatures and after longer persistence times. Given the transfer and persistence characteristics of VOCs from fragrance, there is potential for fragrance to be used as a form of trace in forensic reconstruction approaches. 相似文献
13.
Two experimental studies were undertaken to investigate the processes of reincorporation and redistribution of trace evidence on garments when worn by a suspect or a victim (reincorporation) or after the garments have been seized and packaged for subsequent forensic analysis (redistribution). The first experiment utilised UV powder, an established proxy for geoforensic trace particulates and the second experiment utilised daffodil pollen transferred onto garments under conditions that mimicked forensic reality. It was demonstrated that reincorporation of trace particulates occurs from upper to lower parts of the same garment and also from upper garments to lower garments. Reincorporation also occurred to all areas of the lower garments, however the highest concentration of particulates was found to be the lap area of the jeans. Particulates also tended to be preserved around technical details such as stitching or relief design features of the garments. Thus the decay of particulates after a contact has been made does not necessarily involve a loss of those particulates from the entire system. These findings have implications for the interpretation of trace evidence when seeking to establish the source of initial contacts or the chronology of pertinent events. The second study demonstrated that folding and packaging items of clothing leads to a redistribution of any trace particulate evidence that is present thereby eliciting an alteration in the spatial distribution of that evidence. There is therefore a necessity to take the context of trace evidence into account and also to follow protocols that are sensitive to these aspects of trace evidence behaviour as a failure to do so may have consequences for the correct interpretation of such evidence. 相似文献
14.
目的应用Ion Torrent PGM^TM平台对人线粒体基因组全序列进行分析检测。方法采集39名辽宁汉族无关个体以及4个母系家系的14名相关个体样本,应用SequalPrep^TM Long PCR试剂盒进行扩增,应用Ion Shear^TM Plus Reagents试剂盒和Ion Plus Fragment Library试剂盒等构建文库,并在Ion Torrent PGM平台上进行线粒体基因组全序列测序。结果在39名无关个体共观察到39种单倍型,在396个位置观察到了397种碱基变异。无关个体中出现的变异位点数目为25~53个,平均每个个体出现36.2个碱基变异。4个母系家系中每个家系成员间具有完全相同的mtDNA单倍型,严格遵守母系遗传。结论采用本研究建立的人线粒体基因组全序列的测序检验法,可显著提高mtDNA的个体识别能力,在法庭科学领域中有较好的应用价值。 相似文献
15.
杨玲 《西南政法大学学报》2002,4(3):102-105
本文通过对狭义瑕疵证据及其证明力的辨析,反驳了在此问题上的许多片面观点和认识,强调了现代社会刑事诉讼中的证据对人权保护的重要意义,并指出:在刑事诉讼中对瑕疵证据一律不得采信,瑕疵证据不能成为定案的根据。 相似文献
16.
计算机犯罪中的电子证据研究 总被引：2，自引：0，他引：2
随着计算机技术的推广运用 ,计算机犯罪不断发展变化。证实计算机犯罪最主要的证据是电子证据。电子证据具有技术性、易变性、隐蔽性和虚拟性的特点 ,属于书证。直接言词规则、最佳证据规则及我国现行法律规定并不影响电子证据的证据价值。电子证据要通过客观性、相关性和合法性的查证。 相似文献
17.
目的调查玉溪汉族人群15个STR基因座的遗传多态性,并分析与国内部分地区汉族群体的遗传关系。方法采用AmpFLSTR Identifiler试剂盒,复合扩增15个STR基因座,计算基因频率及法医学参数;收集国内其他10个群体的遗传学资料进行遗传距离和聚类分析。结果玉溪汉族群体15个STR基因座等位基因及基因型分布符合Hardy-Weinberg平衡定律,PD值在0.790 6～0.968 1之间,PE值在0.315 9～0.733 5之间,PIC值在0.554 6～0.856 4之间,15个基因座累积个体识别力为0.999 999 999 999 999 99,累积非父排除率为0.999 998。不同地区汉族群体间遗传距离分析提示,玉溪汉族与成都汉族遗传距离最近(0.004 0),其次是河南(0.004 5)和潮汕(0.004 7);内蒙古最远(0.036 1)。结论云南玉溪汉族15个STR基因座具有较高的遗传多态性,适于该群体的法医学应用,遗传关系分析结果可为该群体的起源、迁徙及与其他群体的遗传关系分析提供参考。 相似文献
18.
19.
论我国民事诉讼中“新的证据” 总被引：1，自引：0，他引：1
“新的证据”的规则是证据规则中的必要组成部分。依据《民事诉讼法》和《民事诉讼证据规则》,可以界定新的证据的含义及其特点。新的证据的排除和认同要根据不同的审理程序和情形来进行。一方当事人提出新的证据,对方当事人可以通过不同的途径,在合理期限内提出抗辩。此外,由于提交新的证据而产生的合理费用,要根据公平原则,在符合一定条件时,由当事人分担。 相似文献
20.
行政程序中的证据规则及其立法问题,在理论上和实践中一直未得到应有的重视,究其症结在于学术界和实务界对行政证据规则和诉讼证据规则的关系缺乏科学的认识.寻求两者之间科学合理的划分标准,发现其中的多样化联系,以及建构完善的行政证据规则体系,具有重大的理论价值和实践意义. 相似文献