Gunshot residue in Chicago police vehicles and facilities: an empirical study

Suspects in shooting investigations in Chicago are routinely transported in department vehicles and detained in department facilities prior to gunshot residue (GSR) evidence collection. The GSR test results are used to associate the suspect with primary exposure to GSR. The potential for these vehicles and facilities being sources of secondary GSR contamination needed to be determined. A total of 201 samples were collected from randomly selected vehicles and detention facilities. The sampling collected trace materials from surfaces that suspects' hands may contact during the arrest process. These samples were examined for the presence of GSR particles using scanning electron microscopy. Upon completion of the automated analysis, those particles that met an initial GSR screening criterion were relocated and reanalyzed. The locations where GSR particles were recovered allowed us to make recommendations to the Chicago Police Department with regard to transporting and detaining these suspects. The low number of GSR particles recovered suggests that the potential for secondary contamination, although present, is relatively low.     

Quick Screening of Crystal Methamphetamine/Methyl Sulfone Exhibits by Raman Spectroscopy

Abstract: The analysis of mixtures of “crystal meth” (usually comprised of methyl sulfone [MS] and methamphetamine [MA]) by gas chromatography‐mass spectrometry (GCMS) is routine in many forensic drug laboratories. The utilization of Raman spectroscopy for the identification of such mixtures quickly and without the need for a separation technique is discussed. Samples were dissolved in water and Raman spectra of the resulting aqueous solutions were collected. By comparing these spectra to spectra of methylsulfone and MA mixtures of known composition, an indication of the composition of the sample can be obtained in only a few minutes. This spectral comparison also can be used as a semi‐quantitative analysis of MA concentrations in such exhibits.     

Optical Characterization of Some Modern “Eco‐Friendly” Fibers*

Abstract: Fibers that are termed “eco‐friendly” or “biodegradable” by manufacturers are increasingly being used in textile products such as apparel and carpeting to appeal to the ever more environmentally aware public. As such, these modern fibers are expected to begin showing up more often in forensic casework, and it is important that the forensic examiner recognize them. This study employed polarized light microscopy (PLM) and Fourier transform infrared (FTIR) microspectroscopy to characterize selected fibers of azlon, polylactic acid (PLA), cellulose composites of alginate or chitin, and bamboo (viscose rayon). Fiber cross‐sections, refractive indices, melting points, solubilities, and FTIR measurements were conducted. Results indicate that the azlons and PLA fibers are easily distinguishable from other textile fibers by their optical and chemical properties. The cellulose composites show only small differences in comparison with other cellulose‐based fibers, while bamboo viscose rayon is indistinguishable from normal viscose rayon.     

固相微萃取技术在毛发药物分析中的应用

固相微萃取（SPME）可与GC/MS、HPLC/MS等在线联用,实现分离、分析一体化的特点为其在毛发药物分析中的应用提供了可能性和良好的应用前景。本文对SPME技术在毛发中滥用药物如苯丙胺类、美沙酮、大麻、可卡因、利多卡因等及其相应代谢产物的分析研究及应用进展做一综述。     

Visualization of Aged Fingerprints with an Ultraviolet Laser

Detection of aged fingerprints is difficult because they can degrade over time with exposure to light, moisture, and temperature. In this study, aging fingerprints were visualized by time‐resolved spectroscopy with an ultraviolet‐pulsed laser. Fingerprints were prepared on glass slides and paper and then stored under three lighting conditions and two humidity conditions for up to a year. The fluorescence intensities of the fingerprints decreased with time. Samples were stored in the dark degraded less than in sunlight or under a fluorescent lamp. Samples were stored under low humidity degraded less than under moderate humidity. As the storage period increased, a fluorescence emission peak appeared that was at a longer wavelength than the peak visible in earlier spectra. This peak was used for visualization of an aged fingerprint over time. An image of the fingerprint was not initially visible, but an image appeared as the time since deposition of the fingerprint increased.     

Controversial Suicide Case Using a Submachine Gun with a Sound Suppressor—The Need of Team Work of Forensic Chemistry and Firearm Examiners

Evidence materials in a presumed suicide case were studied by a firearm examiner and a forensic chemist. The victim's body with double gunshot wounding in his forehead, a machine gun in the sustained fire mode with a silencer, and four cartridge cases were found. Examinations of the evidence, the case file studies, and experiments dedicated to the case were carried out. Relationships between the placement of cartridge cases and the gun were established using a fast camera. The distributions of gunshot residues on the evidence materials and within the comparative gunshot patterns were studied by means of optical and electron microscopy, X‐ray microanalysis, and infrared spectroscopy. The shooting distance was assessed to be 30 cm or more, whereas the greatest distance that could have been achieved by the victim himself was about 11–13 cm. The obtained results supported the version of homicide rather than suicide.     

浅析深圳市处理医患纠纷的新模式——仲裁

既往由医疗损害引起的狭义医患纠纷的处理模式包括协商解决、行政调解、民事诉讼。现阶段我国医患纠纷的数量日益增多,有必要推出更多的解决途径。深圳市新推出的医患纠纷仲裁模式则更为医患双方认可,其最大优点是同时可以兼顾中立性、权威性与高效率,但单独采用这种模式仍有一些问题,理想的模式是强制推行医疗损害责任保险制度,采用仲裁模式解决医患纠纷。     

二乙酰吗啡盐酸盐标准物质的研制（2）-定值和不确定度评定

目的对研制的二乙酰吗啡盐酸盐标准物质进行定值,并评定定值结果的不确定度。方法采用定量核磁共振法和质量平衡法进行定值;采用液质联用法用于有机物杂质的定性分析,采用电感耦合等离子质谱法、离子色谱法、顶空-气质联用法和卡尔费休滴定法测定无机阳离子、阴离子、挥发性有机溶剂残留和水分等杂质的含量。结果定量核磁共振法的纯度为95．6％,不确定度为0．13％;质量平衡法的纯度为95．3％,不确定度为0．93%。结论二乙酰吗啡盐酸盐标准物质的纯度值为95．6％,扩展不确定度为1．2％（k=2）。     

超声辅助固相萃取-HPLC法测定不同地区缴获鸦片样品中生物碱

目的本文建立了超声辅助固相萃取-HPLC法定量测定缴获鸦片样品中吗啡、可待因、蒂巴因、罂粟碱、那可汀5种生物碱并同时检出6种未知化合物的方法。采用主成分分析法区分不同地区缴获的鸦片样品。方法采用超声辅助固相萃取法提取生物碱,XDB-C18（5μm×4.6mm×250mm）色谱柱,流动相为10mM的1-庚烷磺酸钠（pH 3.2）和乙腈,梯度洗脱,紫外检测器检测。结果该方法的定量限为0.58~2.78 mg/kg。添加水平在0.2～1.5mg/mL范围内,平均加标回收率为81.0%～99.2%,相对标准偏差为1.6%～5.0%。结论本方法重现性好、定量准确,满足定量检测鸦片中生物碱含量并对不同产地鸦片进行分类的需要。     

颅脑损伤后昏迷与社会活动、生活功能的相关性探讨

目的研究颅脑损伤后格拉斯哥昏迷指数（GCS）评分、昏迷时间与社会功能缺陷筛选量表（SDSS）值、日常生活活动能力评价表（ADL）值的相关性。方法选取常州市德安医院司法鉴定所及苏州大学司法鉴定所颅脑损伤被鉴定人281例,详细记录损伤部位、损伤程度、昏迷时间、GCS评分,是否手术治疗、是否为多发伤;同时应用SDSS量表及ADL量表评分,并进行统计分析。结果 GCS评分与颅脑损伤6个月后SDSS值低度相关,与ADL值中度相关;昏迷时间与颅脑损伤6个月后SDSS值低度相关,与ADL高度相关。结论 GCS评分及昏迷时间与颅脑损伤后ADL值、SDSS值具有一定的相关性,对颅脑损伤司法鉴定具有一定的参考价值。