Forensic applications of infrared imaging for the detection and recording of latent evidence

We report on a simple method to record infrared (IR) reflected images in a forensic science context. Light sources using ultraviolet light have been used previously in the detection of latent prints, but the use of infrared light has been subjected to less investigation. IR light sources were used to search for latent evidence and the images were captured by either video or using a digital camera with a CCD array sensitive to IR wavelength. Bloodstains invisible to the eye, inks, tire prints, gunshot residue, and charred document on dark background are selected as typical matters that may be identified during a forensic investigation. All the evidence types could be detected and identified using a range of photographic techniques. In this study, a one in eight times dilution of blood could be detected on 10 different samples of black cloth. When using 81 black writing inks, the observation rates were 95%, 88% and 42% for permanent markers, fountain pens and ball-point pens, respectively, on the three kinds of dark cloth. The black particles of gunshot residue scattering around the entrance hole under IR light were still observed at a distance of 60 cm from three different shooting ranges. A requirement of IR reflectivity is that there is a contrast between the latent evidence and the background. In the absence of this contrast no latent image will be detected, which is similar to all light sources. The use of a video camera allows the recording of images either at a scene or in the laboratory. This report highlights and demonstrates the robustness of IR to detect and record the presence of latent evidence.     

Validation of LAB color mode as a nondestructive method to differentiate black ballpoint pen inks

Nondestructive digital processing methods such as lab color mode (available in Adobe Photoshop) are emerging as alternative methods for forensic document examiners to use when attempting to differentiate writing instrument inks. Although these techniques appear to be viable, little data currently exists regarding the known or potential error rates associated with these techniques. Without adequate data, the validity and reliability of these techniques, including lab color, can not be established. In an attempt to begin to address these issues, 44 black ballpoint ink pens were obtained and used to create 990 pen-pair samples for analysis using established lab color mode techniques. No erroneous findings of "different" were reported following the examination of the known pen-pair combinations in which the same pen was used to create the samples (n = 44). Of the remaining 946 samples, 737 pen-pair samples were differentiated using the lab color mode method, while 209 samples were unable to be differentiated and were recorded as either being "similar" (n = 153) or "unsure" (n = 56). Comparison of the lab color mode results with the results obtained through additional testing using traditional infrared reflectance and infrared luminescence test methods showed that lab color differentiated 102 pen-pair samples (11%; 102/946) that were not differentiated using a VSC-4C.     

Writing the Rwandan Genocide: The Justice and Politics of Witnessing after the Event

This paper tries to read together three texts that refer to the Rwandan genocide and to draw attention to certain paradoxes that emerge from the way in which the texts might be said to talk to and past each other. The overall intention is to throw light on the complications in witnessing such an event, and to themes of justice and politics that arise.

"实验文体写作"现象的动因与意义

各种相对定型的文体,在写作中长期被作为特定“内容”相匹配的形式规范;而当下互联网上和纸媒文学领域出现的“实验文体写作”,却正显示出打破固定规范的文体变革趋势;究其动因,是由于发展变化的社会生活和现代人更趋丰富多元的心理内容,需要寻求与之相适应的、新的文体形式予以表达。“实验文体写作”是时代发展导致的必然现象。     

印文与文字交叠时序的无损鉴定

在印文与文字交叠时序的鉴定中应倡导的准则是:无损至尊。书写笔迹、打印文字与印文交叠时序的鉴定,均有合适的方法可供使用。在鉴定中还要注意一些问题,养成一种正确的思维方式。     

Distinguishing Characteristics of Robotic Writing

Advances in robotic handwriting technology create new challenges for forensic document examiners. In the past, devices such as the autopen were used to replicate signatures of government officials and corporate companies. In today's technology, companies such as Bond utilize robots to create written documents, which mimic natural patterns of handwriting. They generate customizable written samples by simulating pen movements and letter formations. Four forensic document examiners were given various reproduced questioned documents and utilized a modified ACE‐V (analysis, comparison, evaluation, verification) methodology to determine their genuineness. Examiners were able to make a distinction between the human writing samples and the skilled robotic equivalents. Several distinct features that are not seen in natural handwriting, such as even pen pressure and the superimposition of letterforms were observed in the robotic samples. Careful examination of identifying features of the Bond produced documents resulted in an opinion of nongenuineness.     

The admissibility and persuasiveness of expert evidence

Parenting plan evaluators are expert witnesses who offer their opinion. Courts in common law jurisdictions generally do not accept evidence of an opinion as it is not considered to be reliable evidence from which to establish a fact. An exception to that general principle is expert opinion evidence. In short, an opinion from a person with specialized knowledge or expertise about the area in which they are an expert may be sufficiently reliable to form an evidentiary basis from which to make a finding of fact, provided the opinion meets certain criteria. These criteria will be discussed in this article, as well as what is relevant, reliable and persuasive evidence. The relevant legal principles will be examined in an historical and contemporary, theoretical and practical context. The authors reflect on their considerable experience as consumers of expert evidence and apply this to parenting plan evaluations, as well as considering future challenges in the field.     

大学英语写作课教学刍议

英语写作课教学始终是英语教学的薄弱环节.写作教学不是孤立的,它有赖于其他教学环节.只有学生打下了扎实基础,积累了一定语言知识,写作能力才能提高.在写作的教学过程中,教师应当对各种教法兼容并蓄,并用不悖.要根据学生的学习状态以及教学的课时安排扬长避短,运用好不同的教学方法.