以币拓方式识别假币之应用论证

以币拓水印方式识别可疑货币,操作简单,效果明显,适用面广,对于具有非凹版印刷的后加水印的假币均能有效识别,可弥补以透光检验水印方式识别可疑货币法之不足。而且,币拓法的检验对象还可进一步推广到可疑货币上除水印以外的其他所有本身应为凹凸结构但采取非凹版印刷方法印制的图文上面去。     

Utilization of paw prints for species identification in the Canidae family

In this report, the bodies of six skinned animals were submitted to the Oklahoma Animal Disease Diagnostic Laboratory for necropsy examination as authorities were concerned these animals were domestic dogs. Given the condition of the animals, identification of the animal species could not be based on traditional physical characteristics such as size, fur characteristics, and ear characteristics. The paw prints from these animals were characterized based on size, heel pad architecture, and claw characteristics. The length of the forepaws measured 3-3.25 in., four toes were observed and only the claws of digits 3 and 4 were identified, and the heel pad had a pronounced three-lobed rear margin. The rear margin of the heel pad of the hind foot was of circular shape with two slightly forward-pointing crescents laterally. Based on the features of the paw print it was determined that the animals necropsied were coyotes.     

同源激光雕刻橡塑印章印文的鉴别方法

目的找出同源激光雕刻橡塑印章印文之间的特征差异,建立检验鉴定此类印章印文的鉴别方法。方法制作14枚同源激光雕刻橡塑印章,借助文件仪、显微数字分析仪等仪器观察分析其盖印的印文样本。结果找出了各种细节特征差异。结论同源性激光雕刻橡塑印章因其规格性特征符合很好,检验鉴定要以细节特征比对为主。     

Study of Color Laser Printer and Photocopier Class Using a Pattern Location Measurement Method

A trace code pattern location measurement approach is proposed. It includes a method that can precisely extract the trace code pattern to identify the color laser printer or photocopier class. In this study, we collected 379 samples from 15 brands, including 129 models and 196 printers or photocopiers. The trace code pattern class is identified. Four class characteristics are used to identify the print source: (i) the relation between the pattern and print output direction; (ii) observation of the shape features from among the trace code pattern units; (iii) the feature arrangement from among the trace code pattern units; and (iv) the arrangement relation of the trace code pattern. Blind testing shows that the accuracy of the proposed method is approximately 96.9% for the Questioned Document Examiners, and 84.3% in the non‐Questioned Document Examiners. It is thus an effective technique for determining a print's color laser printer or photocopier source class.     

Capturing high-resolution digital images for use in forensic document examination

In the past, pattern disciplines within forensic science have periodically faced criticism due to their subjective and qualitative nature and the perceived absence of research evaluating and supporting the foundations of their practices. Recently, however, forensic scientists and researchers in the field of pattern evidence analysis have developed and published approaches that are more quantitative, objective, and data driven. This effort includes automation, algorithms, and measurement sciences, with the end goal of enabling conclusions to be informed by quantitative models. Before employing these tools, forensic evidence must be digitized in a way that adequately balances high-quality detail and content capture with minimal background noise imparted by the selected technique. While the current work describes the process of optimizing a method to digitize physical documentary evidence for use in semi-automated trash mark examinations, it could be applied to assist other disciplines where the digitization of physical items of evidence is prevalent. For trash mark examinations specifically, it was found that high-resolution photography provided optimal digital versions of evidentiary items when compared to high-resolution scanning.     

A comprehensive ATR-FTIR spectroscopic analysis for the identification and differentiation of lip balms

Lip balm may be encountered as physical evidence in cases involving sexual assaults, homicides, and kidnappings. Lip balm can be used as corroborative evidence by providing a potential link between the victim, accused, and the crime scene. For lip balms to be used as evidence, it is important to understand the diversity and their aging process under different conditions. Therefore, in this study, ATR-FTIR spectroscopy in conjunction with chemometric tools such as principal component analysis (PCA) and linear discriminant analysis (LDA) has been used for the objective identification and differentiation of 20 brands of lip balms. Moreover, lip balms on different substrates and wearing effects over time were also investigated. The results show that the PCA-LDA training accuracy was 92.5%, whereas the validation accuracy comes out to be 83.33%. A blind study using pristine samples was also performed which resulted in 80% PCA-LDA accuracy. PCA-LDA prediction of samples on various substrates showed a higher chemometric prediction accuracy for nonporous substrates (glass, plastic, and steel), than for porous substrates (cotton cloth, cotton swab stick, dry tissue paper, and white paper) for samples kept in room temperature and under sunlight for 15 days. The substrate study showed that the samples from various substrates could effectively generate respective spectra which can help in brand-level identification even after several days. The present method demonstrates a potential for lip balm samples to be used in forensic casework applications.     

Does image editing improve the quality of latent prints? An analysis of image-editing techniques in one crime laboratory

Field research within latent print comparison has remained sparse in the context of an otherwise growing body of literature examining the discipline. Studies examining how ACE-V procedures are implemented within active crime laboratories are especially lacking in light of research suggesting significant variability in examiner practices despite standardized ACE-V procedures. To date, no studies have examined a potentially important aspect of the Analysis phase: digital image editing. We provide information on the prevalence and types of latent print image editing within one laboratory (i.e., Houston Forensic Science Center), examine the potential effect of image editing on objective print quality and clarity (i.e., LQMetrics scores), and explore potential examiner differences in editing effectiveness. Results indicate that most latent prints are edited in some manner, and that image editing improves the quality and clarity of print images as defined by an objective quality metric, although examiners varied in their ability to improve the clarity of print images. Findings suggest that formal guidance or documentation of standard editing procedures would likely improve the reliability of examiner conclusions early in the latent print comparison process.     

Spanish-language print media in the USA: A social semiotic analysis of ideological representations in photojournalism

Although Spanish-language media in the USA have grown rapidly since the turn of the century, little scholarship has been dedicated to the semiotic characteristics of these media. This study examines the visual representation of ideologies in 15 news photographs published in Spanish-language print media in the Midwest of the USA with the goals of understanding how ideologies are expressed visually in a culture that has received little treatment in the previous literature and of determining the potential for these photographs to challenge the negative semiotic treatment of Latin@ immigrants in the USA. Following a critical social semiotic approach, the analysis demonstrates how ideologies pattern around the inclusion and exclusion of Latin@s. These ideologies challenge and perpetuate the hegemonic structure, respectively, and as such, indicate the potential for local Spanish-language print media to challenge the negative semiotic representation of Latin@s in the USA while pointing to the need for future research of minoritized media using the social semiotics framework.     

Latent Fingerprint Development on Thermal Paper Using Traditional Ninhydrin and 1,2‐indanedione

Thermal paper poses a significant challenge to latent print development as it tends to change color when traditional fingerprint development formulations are applied to it. In this study, the optimal components of ninhydrin, 1,2‐indanedione, 1,8‐diazafluoren‐9‐one (DFO), and 5‐methylthioninhydrin (5‐MTN) for yielding clear fingerprints on thermal paper were determined by systematically adjusting the relative amounts of the reagents, polar solvents, and the nonpolar diluent petroleum ether, followed by validation on text‐printed thermal paper. Specifically, 3.0% ethyl acetate as the polar solvent in petroleum ether was found to be the optimal combination; the optimal dilution ratios of ninhydrin, DFO, and 5‐MTN original solutions with petroleum ether were 1 to 2, 11, and 7, respectively. The optimal concentration of 1,2‐indanedione in petroleum ether was 0.125 g/L, with a string of 0.5% ethyl acetate in petroleum ether.     

Differentiation of Twenty‐One Glitter Lip‐Glosses by Pyrolysis Gas Chromatography/Mass Spectroscopy*

Abstract: Differentiation of 21 glitter lip‐glosses from seven manufacturers was attempted by pyrolysis gas chromatography/mass spectroscopy. Samples were pyrolyzed on a ribbon probe at 800°C for 20 sec and analyzed with an Agilent^® 6890N Network GC System and Agilent^® 5973 Network Mass Selective Detector with MSD Productivity ChemStation^® Data Analysis software. The total ion chromatograms obtained were examined and differences in the presence or absence of certain chromatographic peaks corresponding to certain pyrolysis products (e.g., styrene, cyclohexane) noted. In cases where the total ion chromatograms between lip‐glosses were similar, select ion profiling was performed. Of the 21 lip‐glosses, 15 were differentiated by either the total ion chromatograms alone or through select ion profiling. Considering that lip‐glosses are typically worn by young women (who are disproportionately victims of sexual assault), this study offers the potential of being able to provide investigative leads in sexual assault investigations with evidentiary samples of this kind.