Digital and Document Examination

Max M. Houck

• Publisher: Academic Press
• Year: 2018
• Print ISBN: 9780128027172
• eBook ISBN: 9780128027394
• Topic: Law
• Subtopic: Cyber Security
• Index: Law

The Advanced Forensic Science Series grew out of the recommendations from the 2009 NAS Report: Strengthening Forensic Science: A Path Forward. This volume, Digital and Document Examination, will serve as a graduate level text for those studying and teaching digital forensics and forensic document examination, as well as an excellent reference for forensic scientist's libraries or use in their casework. Coverage includes digital devices, transportation, types of documents, forensic accounting and professional issues. Edited by a world-renowned leading forensic expert, the Advanced Forensic Science Series is a long overdue solution for the forensic science community.- Provides basic principles of forensic science and an overview of digital forensics and document examination- Contains sections on digital devices, transportation, types of documents and forensic accounting- Includes sections on professional issues, such as from crime scene to court, forensic laboratory reports and health and safety- Incorporates effective pedagogy, key terms, review questions, discussion questions and additional reading suggestions

Section 1

Introduction

Outline

Introduction

Principles of Forensic Science

Forensic Classification of Evidence

Interpretation/The Comparative Method

Key Terms

Review Questions

Discussion Questions

Introduction

Forensic science has a perception problem: We are not CSI but we are not chopped liver, either. The real issue may stem from a lack of core scientific philosophical principles from which to work. Even relatively young disciplines such as chemistry (the recognizable form of which developed in the early 1600s) have established fundamental philosophies from which to work. Forensic science is only about 100 years old, give or take; we have much to work on to rediscover our philosophical base and make it explicit.

One of the obstacles in the process of redefining forensic science as a science is that so much of what gets done is task based, that is, methods. The emphasis on technique distracts from a deeper understanding of not just the how but the why. The philosopher William Barrett in his book, The Illusion of Technique, discussed that, while technicians know what to do, scientists know what to do when something goes wrong because they understand the process more completely:

The technician is called upon to handle the instrument he is assigned to without having necessarily to know how it works…So the biologist need not know the laws of optics on which his microscope has been constructed. The characteristic of technical organization is the subdivision of labor at the specificity of the task assigned. Within science this begets the common situation where one scientist borrows and uses the results of another scientist without having to know clearly on what they are based, or what their finer meaning may be. Now imaging this procedure carried out to the farthest degree. Each link in the chain does what it does without knowing what the whole chain is about. We would end by building a tower of Babel¹ where each layer of the structure cannot communicate with the next.

Barrett (1978, pages 121–122).

As Barrett points out, this problem expands as science becomes more specialized (biologists do not understand optics, chemists do not understand electrical engineering, etc.). This is, in a nutshell, the trouble with forensic science to a large degree. We have a bag of tools but not a wealth of knowledge about how they work.

Digital and documents examination suffers from this perhaps more than other forensic disciplines, the former more than the latter. Recent research in handwriting has lead to great gains in our understanding of how this method works and when it does not, why.

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¹ The Tower of Babel is a Near Eastern story in the Book of Genesis. In the story, at one time, all humanity spoke one language. They agree to build a tower—together—tall enough to reach heaven. God, seeing this attempt to reach him, confounds their speech into many languages and scatters the people across the globe. Thus, humanity could not understand each other and could not finish the Tower. By one account, the tower received its name from the Hebrew word balal, meaning to jumble or to confuse.

Principles of Forensic Science

F. Crispino Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada

M.M. Houck Consolidated Forensic Laboratory, Washington, DC, USA

Abstract

Forensic science is grounded on two native principles (those of Locard and Kirk) and the admission of a few other nonnative ones. This framework is one definition of a paradigm for the discipline to be considered a basic science on its own merits. The science explores the relationships in legal and police matters through the analysis of traces of illegal or criminal activities. In this way, forensic science is seen as a historical science, interpreting evidence in context with its circumstances and originating processes (at source and activity levels).

Keywords

Epistemology; Forensic; Kirk; Locard; Paradigm; Science

Glossary

Abduction Syllogism in which one premise is certain whereas the other one is only probable, generally presented as the best explanation to the former. Hence, abduction is a type of reasoning in which we know the law and the effect, and we attempt to infer the cause.

Deduction Process of reasoning that moves from the general to the specific and in which a conclusion follows necessarily from the stated premises. Hence, deduction is a type of reasoning in which, knowing the cause and the law, we infer the effect.

Forensic intelligence Understanding on how traces can be collected from the scene, processed, and interpreted within an holistic intelligence-led policing strategy.

Heuristic Process of reasoning by rules that are only loosely defined, generally by trial and error.

Holistic Emphasizing the importance of the whole and the interdependence of its parts.

Induction Process of deriving general principles from particular facts or instances, i.e., of reasoning that moves from the specific to the general. Hence, induction is a type of reasoning in which, knowing the cause and the effect (or a series of causes and effects), we attempt to infer the law by which the effects follow the cause.

Linkage blindness Organizational or investigative failure to recognize a common pattern shared on different cases.

Science The intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment. It is also defined as a systematically organized body of knowledge on a particular subject.

Given that it identifies and collects objects at crime scenes and then treats them as evidence, forensic science could appear at first glance to be only a pragmatic set of various disciplines, with practitioners adapting and developing tools and technologies to help the triers of fact (juries or judges) interpret information gained from the people, places, and things involved in a crime. The view could be—and has been—held that forensic science has no philosophic or fundamental unity and is merely the application of knowledge generated by other sciences. Indeed, many working forensic scientists regard themselves mainly as chemists, biologists, scientists, or technicians, and rarely as practitioners of a homogeneous body of knowledge with common fundamental principles.

Even the 2009 National Academy of Sciences National Research Council Report failed to recognize such a concept, certainly blurred by a semantic gap in the terminology itself of field practitioners, who confuse words such as “forensic science(s),” “criminalistic(s),” “criminology,” “technical police,” “scientific police,” and so on, and generally restrict the scientific debate on analytical techniques and methods. An independent definition of forensic science, apart from its legal aspects, would support its scientific status and return the expert to his or her domain as scientist and interpreter of his analyses and results to assist the lay person.

What Is Forensic Science?

In its broadest sense, forensic science describes the utility of the sciences as they pertain to legal matters, to include many disciplines, such as chemistry, biology, pathology, anthropology, toxicology, and engineering, among others. (“Forensic” comes from the Latin root forum, the central place of the city where disputes and debates were made public to be solved, hence, defining the law of the city. Forensic generally means of or applied to the law.) The word “criminalistics” was adopted to describe the discipline directed toward the “recognition, identification, individualization, and evaluation of physical evidence by application of the natural sciences to law-science matters.” (“Kriminalistik” was coined in the late nineteenth century by Hans Gross, a researcher in criminal law and procedure to define his methodology of classifying investigative, tactical, and evidential information to be learned by magistrates at law schools to solve crimes and help convict criminals.) In the scheme as it currently stands, criminalistics is part of forensic science; the word is a regionalism and is not universally applied as defined. Difficulties in differentiating the concepts certainly invited the definition of criminalistics as the “science of individualization,” isolating this specific epistemologically problematic core from the other scientific disciplines. Individualization, the concept of determining the sole source of an item, enthroned a linear process—identification or classification onto individualization—losing sight of the holistic, variable contribution of all types of evidence. Assessing the circumstances surrounding a crime, where the challenge is to integrate and organize the data in order to reconstruct a case or propose alternative propositions for events under exami...

Table of contents

• Cover image
• Title page
• Table of Contents
• Published titles in the Advanced Forensic Science Series
• Copyright
• Dedication
• Senior Editor: Biography
• List of Contributors
• Foreword
• Introduction
• Section 1. Introduction
• Section 2. Digital Devices
• Section 3. Transportation
• Section 4. Documents
• Section 5. Financial
• Section 6. Professional Issues
• Index