The Effects of Polymer Pigmentation on Fingermark Development Techniques

The effectiveness of latent fingerprint development techniques is heavily influenced by the physical and chemical properties of the deposition surface. The use of powder suspensions is increasing for development of prints on a range of surfaces. We demonstrate that carbon powder suspension development on polymers is detrimentally affected by the presence of common white pigment, titanium dioxide. Scanning electron microscopy demonstrates that patches of the compound are clearly associated with increased levels of powder adhesion. Substrates with nonlocalized titanium dioxide content also exhibit increased levels of carbon powder staining on a surface‐wide basis. Secondary ion mass spectrometry and complementary techniques demonstrate the importance of levels of the pigment within the top 30 nm. The association is independent of fingermark deposition and may be related to surface energy variation. The detrimental effect of the pigment is not observed with small‐particle reagent (MoS₂ SPR) or cyanoacrylate (superglue) fuming techniques that exploit different development mechanisms.     

Comparison of four skeletal methods for the estimation of age at death on white and black adults

ABSTRACT: When analyzing human adult skeletal remains, it is often difficult to decide whether a single aging method will give a more reliable age estimation than a combination of methods. This study evaluates four macroscopic indicators for age estimation on 218 American White and Black individuals, ranging in age from 25 to 90 years of age, from the Terry collection. Individuals in the sample were selected to have a balanced race, sex, and age distribution. The following aging methods were applied to each skeleton by one experienced observer: the Suchey–Brooks (SB) pubic symphysis method, the Lovejoy auricular surface method, the monoradicular teeth Lamendin (LM) method, and the I?can (IC) method for fourth ribs. The statistical study involved the evaluation of inaccuracy and bias (based on median age) for each age indicator and the combination of methods using Principal component analysis (PCA). Analysis was performed on the entire sample, then by race, then sex, and then age group (25–40 years, 41–60 years, and >60 years). PCA was the most accurate method for both racial groups when all age groups are analyzed together. When the sample was divided into age groups, SB was the most accurate for young adults (25–40 years) and LM was the most accurate for middle adults (41–60 years). After the age of 60, all methods are highly inaccurate, although IC gives the lowest inaccuracy. As regards bias, the study highlights the tendency of all methods to overestimate the age of young individuals and to underestimate in the older age group. No single skeletal indicator of age at death is ever likely to reflect accurately the many factors that accumulate with chronological age. In fact, one must use as many dental and skeletal indicators as possible. However, in order to maximize the potential of each method, in the final evaluation one should consider mainly the method or methods that have a higher accuracy for a particular age range.     

四氧化钌显现潜手印研究

目的探索显现潜手印的新方法。方法通过实验研究提出四氧化钌显现方法。结果对遗留在白纸、报纸、玻璃及木板等4种客体上的新鲜及陈旧潜手印的显现实验，得出比较理想的显现效果。     

试论单位自首之认定

单位犯罪作为一项崭新的法律制度在1997年已经被全面地载入我国刑法当中,虽然关于单位犯罪的制度已经在我国确立下来,但是关于单位犯罪的自首问题在理论和实践上仍存在着很大争议。文章通过单位自首的实质条件以及形式条件这两方面对如何认定单位自首进行研究和探讨,以期能够对单位自首的刑事立法以及司法实践有所裨益。     

论监狱文化建设的社会正义价值--以监狱建设外观为视角研究中国监狱表层文化

监狱的价值与存在离不开社会认同。社会认同的前提是监狱社会职能的有效实现。在表层物质文化、中层精神文化和深层哲学文化的三个领域,监狱给予社会公众最直观的是以监狱建筑等物质形态景观为代表的表层文化。它以威严、恐惧、不可靠近的特有的社会正义文化信息向社会公众传达社会治理秩序的规则、标准和执行的强制性。监狱建设必须充分考量社会公众的一般认知,以鲜明的监狱物质表层文化发挥监狱的社会职能作用。当下监狱建设应当以现代监狱文化建设的价值内涵为基础,以现代法治要求为根本,认真分析监狱表层文化对于社会治理秩序的影响作用,准确定位现阶段监狱建设的阶段性指导标准,准确表达监狱文化的内涵,更好地实现现代中国监狱建设的社会职能作用。     

A Systematic Study to Understand the Effects of Particle Size Distribution of Magnetic Fingerprint Powders on Surfaces with Various Porosities

This study intends to design magnetite (Fe₃O₄)‐based magnetic fingerprint powders with different particle size distributions. It also investigates the influence of particle size distribution on the visualization of latent fingermarks with as little background staining as possible on the surfaces with various porosities in a systematic way. Two strategies were used to prepare the magnetic fingerprint formulations for this study: milling of coarse magnetite particles for different durations, and mixing of sieved fine particles with different size ranges with coarse particles. Particle size analyses of the prepared magnetic powders, optical microscopy‐based roughness analysis of the surfaces and SEM measurements of the visualized fingerprints and representative powders were performed. Mag2 of the formulations prepared through milling and Mag5 and Mag6 of the formulations prepared through sieving and mixing were more successful in the development of latent prints than the rest of the solutions.     

利用Photoshop CS处理强反光圆柱体上的手印照片

现场勘查中常遇到圆柱体反光表面客体，如防盗金属门窗上的圆管等，因受光面不均匀，容易产生强烈的反光带，拍摄这类客体上的手印痕迹较为棘手，为了有效地获得这类物证，在充分运用近距离照相技术获取手印的数码照片后，再利用Photoshop的图像调整功能，对图像的色调、色相进行合理的调整，会得到良好的图像效果。     

牛IgG2 Fc受体在COS-7细胞表面的稳定表达

将牛IgG2 Fc受体(boFcγ2R)编码区cDNA亚克隆到真核表达载体pcDNA3的巨细胞病毒启动子下游,构建了重组表达质粒pc3bo2R;以重组质粒转染COS-7细胞,用玫瑰花环试验检测boFcγ2R在转染细胞表面的表达,通过G418抗性筛选和连续克隆化,在转染细胞表面稳定表达了boFcγ2R受体分子,转染细胞的玫瑰花环形成率达90%。最后获得稳定表达boFcγ2R受体分子的COS-7转染细胞系,为受体的功能研究提供了良好的技术平台。     

胶带的剥离与粘面上汗潜手印显现方法

犯罪现场遗留的胶带极易相互缠绕粘连成团、成束 ,采取有效的方法对相互缠绕粘连的胶带进行剥离 ,是显现胶带粘面上手印的前提和基础 ,也是甚为关键的问题。可采用机械剥离法和化学剥离法对胶带进行剥离 ,采用照相法、物理显现法和化学显现法对胶带粘面手印进行显现     

蜡质客体上汗潜手印的显现

目的建立蜡质客体上汗潜手印的显现方法;方法遗留在蜡质客体上的汗潜手印,经适量“502”熏显后,用较高浓度的BBD溶液进行染色,在多波段光源的激发下以增强显现效果。结果遗留在蜡面上10天以内的汗潜手印可得到理想结果;结论该方法方便易行,并成功用于检案。