Role of Nanomaterials for Forensic Investigation and Latent Fingerprinting—A Review

The imminent nanotechnology and progressive instrumentations together have vast applications in the field of forensic science. Few prominent examples are gold nanoparticles for improvising the efficiency of polymerase chain reaction and atomic force microscopy for examining ink and bloodstains. Characteristics like distinct ridge details of fingerprints could be obtained by applying different nanoparticles such as silver, zinc oxide, silicon dioxide, aluminum oxide, gold (with silver physical developer), europium, fluorescent carbon, and amphiphilic silica on a range of object surfaces, and among all, gold is most commonly used. Fingerprint is considered noteworthy evidence in any crime scene, and nano-based techniques hold immense future potential in fingerprint investigations. Therefore, this paper focuses on the applications of nanoparticles in developing and detecting the latent fingerprints.     

Juvenile Sexual Murderers: Examination and Classification of the Crime-Commission Process

This study aims to empirically explore the crime-commission process of juvenile sexual homicide offenders (SHOs). First, a comparison between the crime-commission process of juvenile and adult SHOs is undertaken, while as a second step, this study also provides an empirical classification specific to juvenile SHOs. The sample used in this study consists of 55 juvenile SHOs and 281 adult SHOs. A sequential binomial regression was used to compare at the multivariate level the two groups of offenders, while a latent class analysis was used to examine the relationships between each step of the crime-commission process of juvenile SHOs. Our findings suggest that the crime-commission process of juvenile SHOs present differences when compared with adult SHOs. Moreover, we identified four different patterns in juvenile sexual homicide: explosive opportunistic, sadistic, overcontrolled anger, and predator. Theoretical and practical implications in terms of criminal investigations as well as offenders’ management and treatment are discussed.     

两种方法提取汗潜手印DNA的比较研究

目的比较M48和DNeasy○R plant Mini两种方法提取汗潜手印DNA的优劣。方法用M48和DNeasy○Rplant Mini两种方法分别提取16对汗潜手印DNA,并进行DNA定量,比较定量结果。结果 M48法明显比plant Mini法提取到的DNA量多（配对t检验：α=0.05,t=3.45,γ=15,0.002     

上转换发光微粒悬浮液显现手印技术初探

目的 建立NaYF4∶Er,Yb微粒悬浮液显现手印技术方法并界定适用范围与条件.方法 用NaYF4∶Er,Yb微粒悬浮液显现瓷砖、玻璃等19种（各50枚）不同客体上皮脂汗手印,并对结果进行分析比较.结果 该方法对背景复杂的非渗透性客体上的油汗手印显现良好,其效果优于普通ZnO小颗粒悬浮液.结论 该方法操作简便、适用客体广泛、背景干扰少,适合进一步研究推广.     

Latent Print Proficiency Testing: An Examination of Test Respondents,Test-Taking Procedures,and Test Characteristics

Proficiency testing is a key component of quality assurance programs within crime laboratories and can help improve laboratory practices. However, current proficiency testing procedures contain significant limitations and can be misinterpreted by examiners and court personnel (Garrett & Mitchell, 2018). To evaluate some of these limitations, we surveyed latent print examiners (n = 198) after they completed a Collaborative Testing Services, Inc. proficiency test. Additionally, we evaluated test performance and used a quality metric algorithm to evaluate the quality of test prints. Results do not suggest that respondents are dissimilar to the broader examiner population, although they may engage in different behaviors when completing tests versus casework. Findings show that proficiency testing contains prints of high quality and is perceived as both relatively easy and representative of casework. The test discriminated between inexperienced and experienced respondents, and verification procedures were largely ineffective in reducing errors. Objective quality metrics may provide a path forward to improving proficiency testing in a measurable manner.     

DNA recovery after sequential processing of latent fingerprints on copy paper

Forensic examiners must determine whether both latent fingerprint development and DNA profiling can be performed on the same area of an evidence item and, if only one is possible, which examination offers the best chance for identification. Latent fingerprints can be enhanced by targeting different components of fingerprint residues with sequential chemical treatments. This study investigated the effects of single-reagent and sequential latent fingerprint development processes on downstream DNA analysis to determine the point at which latent fingerprint development should be stopped to allow for DNA recovery. Latent fingerprints deposited on copy paper by one donor were developed using three sequential processes: 1,8-diazafluoren-9-one (DFO) → ninhydrin → physical developer (PD); 1,2-indanedione-zinc (IND-Zn) → ninhydrin → PD; and IND-Zn → ninhydrin → Oil Red O (ORO) → PD. Samples were examined after the addition of each chemical treatment. DNA was collected with cotton swabs, extracted, quantified, and amplified. DNA yields, peak heights, number of alleles obtained, and percentage of DNA profiles eligible for CODIS upload were examined. DNA profiles were obtained with varying degrees of success, depending on the number and type of treatments used for latent fingerprint development. The treatments that were found to be the least harmful to downstream DNA analysis were IND-Zn and IND-Zn/laser, and the most detrimental treatments were DFO, DFO/laser, and PD. In general, as the number of treatments increase, the opportunities for DNA loss or damage also increase, and it is preferable to use fewer treatments when developing latent fingerprints prior to downstream DNA processing.     

论中华指纹文化的起源、影响及其非物质文化遗产特质

中华指纹文化是中华民族先人通过对指纹进行长期观察、运用所形成的知识体系和社会实践,从某种程度上讲,其与"四大发明"具有同等意义。数千年来,指纹作为中国人的身份象征、证明凭据和诚信标志,大量应用于社会管理与民间交往等众多领域,成为中华民族认同的文化标识。中华指纹文化是中华民族智慧与创造力完美结合的产物,是中国非物质文化遗产的优秀代表。     

论残缺指印的特点及鉴定方法

指印是手指末节皮肤乳突花纹遗留的印痕,能反映出手指末节形态的结构特征和乳突花纹的结构特征。在司法实践中,残缺指印的出现率很高,而且由于指印面积小,其纹型难辨,纹线数量少、细节特征少,检验残缺指印比较困难,用常规的鉴定方法难以完成。根据残缺指印的形成特点及鉴定条件从细微处入手、分析形成的原因,通过比对可以得出准确的检验结论。     

检材指纹与样本指纹变化的分析研究

目的 依据数理统计所得出的数据分析检材指纹与样本指纹的变化规律;方法 通过在检材指纹与其相对应的样本指纹上建立直角坐标系,得到各细节特征的坐标参数;再利用数理统计分析两者相对应的各细节特征变化的形成原因及规律;结果 得出捺印时手指作用力方向的变化导致检材指纹与样本指纹细节特征之间产生距离差,手指的扭转变化使两者细节特征产生角度差;结论 两者之间的变化是由于捺印时手指作用力方向不同、大小不同所导致.     

乳突纹线局部形态特征在手印检验中的应用

在手印检验工作中,通过对乳突纹线局部形态特征的种类、特点及检验方法进行研究,并运用实际案例进行分析阐述,论证该类特征在手印检验中具有可操作性,能够提高残缺、少特征等疑难手印的利用率。乳突纹线局部形态特征的应用是对常规特征的重要补充,对手印检验工作具有实际意义。