Forensic Disciplines Research Articles

Digital Imaging Methods as an Aid in Dental Identification of Human Remains

The physical comparison of known (K) and questioned (Q) evidence samples is an accepted tool in numerous forensic identification disciplines (1). A subset of this process is the use of antemortem and postmortem dental radiographs to identify unidentified human remains. This method has been generally accepted for decades (2). The outcome is performed with a considerable degree of accuracy, due in part to a finite pool of possible candidates for identification derived via the NCIC database, passenger lists, and law enforcement Missing Persons reports. This paper describes a dental identification comparison protocol that incorporated digital imaging technology in this process. The computer was used to create digital exemplars of the K and Q evidence that were spatially and quantitatively compared (3). The digital mode allowed direct metric and morphologic comparison through the aid of a digital camera, desktop computer, monitor, and printer. The well-known computer program Adobe Photoshop 5.0 (4) was used to process the digital information in two forensic cases described in this paper. It is a commercially available digital imaging editing program that is operated on laptop and desktop computers possessing sufficient chip speed and RAM (Pentium II or equivalent and at least 76MB RAM) to open the large-size files generated by high-resolution digital capture devices. This program accepts raster-based image formats (e.g. .JPG, .BMP). Photoshop is noted for its diverse imaging functions, which allow the computer monitor to be used as a comparison microscope when Q and K sample images are tiled side-by-side and/or superimposed. Two and three-dimensional Q and K evidence samples can be individually digitized and then independently resized to allow two-dimensional comparison. The investigator also has the ability to create magnified images (200% to 300%) when the original digital image has been captured at near photoquality resolution (300 dpi). The visual comparison of physical features on the computer monitor permits a large field of view and robust digital control over image quality. Photographic measurement and enhancement features of Adobe Photoshop mimics and in some circumstances surpasses the historic use of conventional photographic manipulation in forensic casework. This paper presents two cases processed via routine forensic odontology identification protocols. These protocols had minimal results due to limitations described in the case histories. The additional application of digital methods proved useful in the ultimate identification of these human remains.

US: Dystar — textile colorants

Now approximately 30 years old, the field of digital forensics is arguably facing some of its greatest challenges to date. Whilst currently supporting law enforcement in numerous criminal cases annually, questions are beginning to emerge regarding whether it can sustain this contribution, with digital crime remaining prevalent. In his first live interview in September 2015, Head of MI5, Andrew Parker indicated that individuals are now engaging in computing acts which are beyond the control of authorities, confirming earlier remarks made by British Prime Minister David Cameron in the wake of the Charlie Hebdo attacks. Such comments cast doubt on the future effectiveness of the digital forensic discipline and its ability to effectively investigate those who implement the latest forms of technology to carry out illicit acts. This article debates the controversial question, could we be facing an era where digital crime can no longer be effectively policed?

Ear identification based on surveillance camera images.

Introduction test motivated by the above-mentioned case. As there are no In The Netherlands, as well as in many other countries, the recognized experts in identifying individuals based on use of surveillance cameras has grown rapidly. As a conseimages of ears available at our laboratory, we asked forenquence an increasing number of crimes are recorded on sic experts from several forensic disciplines with a thorough video by surveillance cameras. Therefore, the question of knowledge of individualization principles and laymen to identification of the person(s) appearing in the recorded individualize persons by ear from surveillance camera images is put to the forensic expert more and more frevideo film under closed set assumptions. quently. However, this can be a formidable task, especially The reason for asking laymen and trained investigators is when the recordings are of poor quality and large areas of that the answer to the question whether you have sufficient the body are covered with clothes andlor masks. information to make an individualization or exclusion is Sometimes an expert is asked to, if possible, identify a person based on a visible body part, for example, part of the skin, hands, arms, etc. A similar question was posed to the experts at our laboratory. It concerned several robberies of gas stations in Utrecht, The Netherlands. Video camera surveillance film was obtained from the scenes of the crime. The offender was wearing a baseball cap, shawl and a cloth hanging from the cap thereby covering his face. However, the ears of the offender were visible and the question was raised whether a certain suspect could be identified as being the offender.

A Comparison of Blood Enhancement Techniques

ABSTRACTIt is the responsibility of the forensic specialist to have knowledge of available resources and be able to use these resources to detect, collect and preserve physical evidence during an investigation. The objective of this article is to make members of the forensic law enforcement discipline aware of some of the procedures available to them to enhance blood prints found at a scene or on an exhibit. The Royal Canadian Mounted Police (RCMP) presently uses six bloodstain enhancement techniques: Amido Black, Crowle's Double Stain, Hungarian Red, Leucomalachite Green, Luminol, and forensic light sources. For the purpose of this experiment only the first four mentioned were used. Luminol and the forensic light sources will be discussed in the conclusion of this report.

Computer Forensics Today

When people hear the word “forensics,” it often generates a mental image of the movie series with Jack Klugman as a medical examiner named Quincy. The fact is that there are as many as 25 separate forensic disciplines. They run from forensic accounting to forensic medicine and forensic pathology. The word forensics literally means “a science that deals with the relation and application of a particular field.” Computer forensics is the science that is concerned with the relation and application of computers and legal issues. The proliferation of the computer in society today has pushed the computer forensics discipline to the forefront of business.

A review of major factors contributing to errors in human hair association by microscopy.

Forensic hair examiners using traditional microscopic comparison techniques cannot state with certainty, except in extremely rare cases, that a found hair originated from a particular individual. They also cannot provide a statistical likelihood that a hair came from a certain individual and not another. There is no data available regarding the frequency of a specific microscopic hair characteristic (i.e., microtype) or trait in a particular population. Microtype is a term we use to describe certain internal characteristics and features expressed when observing hairs with unpolarized transmitted light. Courts seem to be sympathetic to lawyer's concerns that there are no accepted probability standards for human hair identification. Under Daubert, microscopic hair analysis testimony (or other scientific testimony) is allowed if the technique can be shown to have testability, peer review, general acceptance, and a known error rate. As with other forensic disciplines, laboratory error rate determination for a specific hair comparison case is not possible. Polymerase chain reaction (PCR)-based typing of hair roots offer hair examiners an opportunity to begin cataloging data with regard to microscopic hair association error rates. This is certainly a realistic manner in which to ascertain which hair microtypes and case circumstances repeatedly cause difficulty in association. Two cases are presented in which PCR typing revealed an incorrect inclusion in one and an incorrect exclusion in another. This paper does not suggest that such limited observations define a rate of occurrence. These cases illustrate evidentiary conditions or case circumstances which may potentially contribute to microscopic hair association errors. Issues discussed in this review paper address the potential questions an expert witness may expect in a Daubert hair analysis admissibility hearing.

Diversity and the Public Space: A Response to Stepp

Professor Stepp is right to begin her study with David Zarefsky's Speech Communication Association presidential address. This address should be required reading for forensics students and read remedially by forensic educators. Zarefsky's address, Postmodern Public: Revitalizing the Commitment to the Public Forum, envisioned the roles that the disciplines of Speech and Forensics could play in revitalizing public space. Two points drawn from Zarefsky's address place Stepp's study in perspective. First, Zarefsky notes: The area of our field which most directly bears on public affairs, the study of argumentation and debate, we too often have treated as an of programs staffed by paraprofessionals and undeserving of our support. And our colleagues in this area have defined their own professional concerns with such insularity that they deprive the rest of us their insight into the conduct of public controversy. (311) If Zarefsky is right, and I think he is, the intellectual backwater of debate has little support from the speech profession, nor can we say that debate educators or students are interested in the mission of reinvigorating the public sphere. Forensics and intercollegiate debate have become insulated activities, and Stepp's research describes one expression of this provincialism. While defenders of the debate status quo, who tend to be our younger colleagues, use representative anecdotes of successful women debaters to suggest that intercollegiate debate is a diverse culture, such claims crumble when juxtaposed with Stepp's careful longitudinal research of the debate system. Her research should put to rest any notion that intercollegiate debate is an open activity, for her study indicates that women and minorities are significantly underrepresented and face significant barriers to participation. Zarefsky makes a second point that serves to frame a friendly quarrel I have with Stepp's analysis of what might be done to encourage diversity in intercollegiate debate. In addressing the complaint made by Nancy Fraser and others that argument and the public sphere are essentially male creations designed to perpetuate the patriarchy, Zarefsky observed: The growing involvement of women in recent decades has brought once issues into the public sphere, ranging from child care and pay equity to domestic violence and sexual harassment. These once were trivialized as women's issues. No longer. We have far to go, of course. But the record to date, in my opinion, should convince feminists not to reject the ideal of the public sphere but, rather, to pursue it more vigorously. (312) If we believe that Zarefsky is right, then we should resist attempts by some scholars like Fraser, Sally Gearhart, and others to abandon the public space and argument for the private sphere and non-competitive dialogue. We must not forgo any ethical form of evidence, thinking, logic, or perspective in teaching students how to argue in the public sphere. In her admirable attempt to discern the reasons why the debate culture is not open, Stepp observes that tournament debating is characterized by tubs of evidence, information processing, linear thinking, deductive thinking, control, objectivity, and independence. These characteristics are associated with masculine role stereotypes. Quoting Rebecca Bjork and Carrie Crenshaw, Stepp argues that women debaters find themselves in a culture of symbolic violence. She then suggests that there is a feminist view that humans are storytellers and we make our decisions by choosing the most appropriate story instead of refuting arguments. Although academic debate may overemphasize external evidence, deductive logic, and objectivity, I fear Stepp verges on conflating verbal aggression with several legitimate forms of reasoning, and that the ability to command some control, objectivity, and independence are essential habits and skills necessary for effective advocacy. …