Determination of blood-harbored 2′-diclazepam with auto-spe and gc-ms/ms

Objective To develop a GC-MS/MS method for determination of 2′-diclazepam in blood. Methods The sampling blood was extracted via HLB cartridge (a product from Waters Corporation, enabling operation of the auto-SPE (solid-phase extraction) for this determination) that was eluted with ethyl acetate, having the collected eluate subjected to GC MS/MS analysis. Results For the 2′-diclazepam tested, a linear relationship was present between the concentration and peak area from the calibration curve in the range of 20 ～ 20μg/mL, demonstrating the limit of detection (LOD) being 10ng/mL. Moreover, the average recoveries were shown within the range of 81.8%~90.4%, and the relative standard deviations among 4.89%~5.47%. Conclusion The here-established method is of high sensitivity, selectivity and strong operability, suitable for determination of diclazepam in blood. © 2021, Editorial Office of Forensic Science and Technology. All rights reserved.     

子弹弹头及弹壳成分比较研究

目的对子弹物证进行成分分析可为涉枪案件的侦查提供科学依据。本实验旨在通过研究子弹弹头及弹壳的元素组成快速区分不同子弹,为推断子弹来源提供关键信息。方法收集不同厂家在1958-2019年不同批次生产的多种型号的子弹样品53份,应用扫描电镜能谱法(SEM/EDX)对样品的弹头内芯、弹头披甲和弹壳金属成分进行研究。结果结果显示多数子弹弹头内芯由纯铅构成,部分批次较晚的弹头为铅锑合金,另有两枚批次较早子弹为铁弹头;除六枚5.6mm运动步枪弹的弹头披甲以及四枚791厂样品的弹壳无明显特征外,其余子弹的弹头披甲和弹壳均为三类铜锌合金中的一种:含铜量83.7%~84.7%、87.6%~90.6%以及67.0%~69.8%的铜锌合金。同型号同厂家子弹所使用弹头披甲及弹壳材料的特征相似,同型号不同厂家、同厂家不同型号的子弹弹头披甲和弹壳材料则具有一定差异。近六十年来121厂样品子弹弹头披甲均为含铜量87.6%~90.6%的铜锌合金,弹壳材料为含铜量67.0%~69.8%的铜锌合金,其为该厂固定使用的铜锌合金原材料的可能性较高。791厂样品中有四种型号的子弹弹壳均为含锰量0.7%~0.9%的铁锰合金,这种合金在其他厂家并未出现,其为791厂弹壳特征原材料的可能性较高。结论掌握子弹弹头及弹壳的元素组成特征可以对不同子弹进行有效识别。     

Holistic Representation: A Randomized Pilot Study of Wraparound Services for First‐Time Juvenile Offenders to Improve Functioning,Decrease Motions for Review,and Lower Recidivism

Mental health diagnoses, substance abuse issues, and school problems are often cited as contributors to adolescents’ involvement with the juvenile justice system. Yet, few youth receive assessment, evaluation, or intervention prior to their involvement with the juvenile courts. This pilot study evaluated whether providing a randomized trial of wraparound forensic social work services in addition to court‐appointed legal services would improve functioning, decrease motions for review, and lower recidivism for first‐time juvenile offenders. Findings indicate statistically significant improvement for youth receiving wraparound services on six out of eight measures. A case study example is provided and implications for service provision are explored.     

司法证明的性质：作为似真推理工具的概率

以贝叶斯分析为代表的概率论,是改变了人类生活之现代科学成就中至关重要的组成部分。然而,它并非是铸就这种成就的唯一认知工具。法庭科学和法律以多种方式关联,但同时又有天壤之别。法庭科学,如同其他任何科学一样,致力于将复杂性降至允许精心设计研究并精确解释的可控水平。法律制度却无法享受这种奢华,且必须在有限时间内应对不可计数、变化多端的人类社会复杂性。司法证明运用包括概率论在内的多种认知工具,以辅助似真推理,但归根结底,它不能被简化为数字和数学公式。     

Quantitative evaluation of the results of digital forensic investigations: a review of progress

Unlike conventional forensics, digital forensics does not at present generally quantify the results of its investigations. It is suggested that digital forensics should aim to catch up with other forensic disciplines by using Bayesian and other numerical methodologies to quantify its investigations’ results. Assessing the plausibility of alternative hypotheses (or propositions, or claims) which explain how recovered digital evidence came to exist on a device could assist both the prosecution and the defence sides in criminal proceedings: helping the prosecution to decide whether to proceed to trial and helping defence lawyers to advise a defendant how to plead. This paper reviews some numerical approaches to the goal of quantifying the relative weights of individual items of digital evidence and the plausibility of hypotheses based on that evidence. The potential advantages enabling the construction of cost-effective digital forensic triage schemas are also outlined.

Key points

• The absence of quantified results from digital forensic investigations, unlike those of conventional forensics, is highlighted.
• A number of approaches towards quantitative evaluation of the results of digital forensic investigations are reviewed.
• The significant potential benefits accruing from such approaches are discussed.

     

Identification of mongoose (Genus: Herpestes) species from hair through band pattern studies using discriminate functional analysis (DFA) and microscopic examination

India is home to seven species of mongoose (Herpestes sp). Mongooses are being poached primarily for their hair, which is used in the production of painting and shaving brushes. Prior to September 2002, mongooses were listed under Schedule-IV of the Wildlife (Protection) Act 1972 (India). Indiscriminate poaching of the mongoose created an immediate threat to their survival and hence mongooses have now been placed under Schedule-II of the Wildlife (Protection) Act-1972 (India). In order to convict a person under this legislation, species identification of case related samples is necessary. Four species of mongoose i.e. H. edwardsii, H. smithii, H. palustris and H. urva were characterised by performing discriminate functional analysis (DFA) on measurements of their dorsal guard hair banding pattern and by microscopic hair characteristics (Cuticular, medullar and cross section). It was possible to distinguish between the four species studied, based on both these methods.     

正常、大声两种说话状态下语音的声学差异及对声纹鉴定的影响

本文主要通过对正常、大声两种说话状态下的普通话中三个单元音[a]、[i]、[u]的声强、时长、基频、谐波振幅差值、共振峰等声学参数的分析,综合比较了各参数的变化规律,发现大声说话时的语音并非正常语音的简单放大,二者不仅在声强上存在差别,同时在频率域上也发生了重要变化。同一人不同状态下发音的频谱特征差异性较大,同种状态下发音的相似性、可比性较强,为此,声纹鉴定中应尽量选取状态相同的语音进行比对。     

Comparison of simulated human dermal bitemarks possessing three-dimensional attributes to suspected biters using a proprietary three-dimensional comparison

The infliction of a bite is a four-dimensional space–time event that is ideally analyzed with three-dimensional (3-D) technology. Comparison of 2-D images (photographs) of a bitemark with a 3-D replica of a suspect's dentition is challenging. The authors present a technique that produces 3-D images of indented marks and dentitions for comparisons. Study models and corresponding dental-wax bites were digitized by 3-D scanning, and comparison overlays were generated using DentalPrint^© software. The effectiveness of the method was analyzed by determining the area under receiver operating characteristic (ROC) curve and the sensitivity, specificity and 95% confidence interval (CI) for each cut-off point. An area under the ROC curve of 0.953 (SE = 0.029; 95% CI = 0.893–0.985) and high sensitivity and specificity values were obtained for 104 comparisons made by an expert examiner, who correctly identified 92.3% of matching dentitions and 98.7% of non-matching dentitions. This technique can be considered a highly accurate method of bitemark analysis, although indentations must be present in the injury, limiting the cases that can be resolved. A comparative study of the same dentitions using 2-D bitemark photography confirmed the superiority of the new approach.     

Voltammetric determination of cocaine in confiscated samples using a cobalt hexacyanoferrate film-modified electrode

In this work, a fast, non destructive voltammetric method for cocaine detection in acetonitrile medium using a platinum disk electrode chemically modified with cobalt-hexacyanoferrate (CoHCFe) film is described. The deposition of CoHCFe film at platinum disk (working electrode) was carried out in aqueous solution containing NaClO₄ at 0.1 mol L⁻¹ as supporting electrolite. Stability studies of the film and subsequent voltammetric analysis of cocaine were made in acetonitrile medium with NaClO₄ at 0.1 mol L⁻¹ as supporting electrolite. A reversible interaction between cocaine and CoHCFe at the film produces a proportional decrease of original peak current, due to the formation of a complex between cocaine and cobalt íons, with subsequent partial passivation of the film surface, being the intensity of current decrease used as analytical signal for cocaine. A linear dependence of cocaine detection was carried out in the range from 2.4 × 10⁻⁴ to 1.5 × 10⁻³ mol L⁻¹, with a linear correlation coefficient of 0.994 and a detection limit of 1.4 × 10⁻⁴ mol L⁻¹. The analysis of confiscated samples by the proposed method indicated cocaine levels from 37% to 95% (m/m) and these results were validated by comparison to HPLC technique, being obtained good correlation between both methods.     

Partial bowel obstruction in a 2-month-old child. A delayed diagnosis of anal abuse

We present the case of an anal sexual abuse involving a 2-month-old boy, who was admitted to the Pediatric Surgery Unit of the University of Padua for low bowel obstruction. The infant had been already hospitalized for 3 days in a peripheral hospital and treated with daily rectal wash-outs for a fecaloma. Only after a careful interpretation of the plain abdominal radiograph, along with the performance of a rectoscopy and a laparotomy, a vegetable foreign body (about 3 cm in diameter and 7 cm in length) was discovered in the sigma. The morphology and dimensions of the foreign body, as well as its location, left no doubt about the etiology of the partial bowel obstruction, proving that it was clearly related to an anal sexual abuse.