Scientific Examination of Documents

Methods and Techniques, Fourth Edition

David Ellen, Stephen Day, Christopher Davies

• Publisher: CRC Press
• Year: 2018
• eBook ISBN: 9780429959325
• Topic: Law
• Subtopic: Criminal Law
• Index: Law

Revised and expanded to reflect the most recent innovations in the field, The Scientific Examination of Documents, Fourth Edition is a handy, accessible volume detailing current best-practices for forensic document examination.

Since the first edition published in 1989, there have been drastic changes in the field of forensic document examination—both from the use of the analytic techniques available to the professional examiner—and the changes to technology in office and printing equipment and inks. The purpose of analyzing any material used in the production of a questioned document, such as an ink or a piece of paper, is to compare it with another material elsewhere in the questioned document itself—or on another document—to determine whether or not they share a common origin. There may also be a need to provide information for the investigator about the possible origins of the document.

This latest edition reflects the myriad changes and advances that have occurred in the last 10 to 15 years. Topics covered include: current thinking on handwriting interpretation; accidental and deliberate modification of handwriting; the proper collection of samples; a discussion of shredded documents; professional accreditation standards, qualifications, and training; and modern digital imaging and analysis of documents and handwriting utilizing software and imaging, including reconstruction of an image from erasures, obliteration and other document altering methods. A new section addresses cognitive bias and Chapter 8 is completely updated to cover the advances in print and photocopied documents, based on current technology, and analytical developments in the comparison of such documents.

Key features:

• Discusses issues regarding handwritten, photocopied, and printed documents—including inkjet versus digital printing
• Presents the advances and capabilities modern office fax, photocopy, and printing technologies—and implications for document examination
• Details and reinforces the importance of ensuring proper scientific methods during an examination
• Addresses current Raman spectroscopy, UV-VIS, mass spectroscopy, and SEM analysis techniques
• Highlights the importance, and implications, of biological and fingerprint evidence from documents that can be collected, examined, and utilized in a case

The Scientific Examination of Documents, Fourth Edition serves as an invaluable resource to established professionals, those just entering the field, and legal and investigative professionals outside the discipline who have a professional interest dealing with questioned documents in the course of their work.

1

Introduction

Within the wide field of forensic science, the scientific examination of documents has one purpose: to provide information about the history of a document for the benefit of a court of law or, before that, to an investigating police officer or other investigating agent seeking evidence that might be present in the document. The same philosophy that pervades forensic science applies to document examination—the application of scientific methods and techniques to the problems relevant to the situation.

Scientific Method

The scientific method is a way of thinking. It is about the study of observed phenomena and the seeking of a correlation between them based on the philosophy that there is order and consistency in the universe. Observations about the heavens, animals, or chemical changes can be and have been made for many centuries, but it is the essentially scientific process of discovering a pattern behind these observations that has led to the technological progress of the last century or so.

The scientific method of correlating observations is to construct a hypothesis and test it by other observations, measurements, and specially devised experiments. If these confirm the hypothesis, it stands, but if not, a new hypothesis must be sought and tested. Thus a corpus of knowledge is built up that can be relied upon to provide a basis for extending the process further.1

Science, however, is more than philosophy; it has a purpose. The exploitation of scientifically based discoveries, mostly for the good of mankind, has been the hallmark of the nineteenth and twentieth centuries (and continues into the twenty-first century), but another benefit has been in the development of methods of analysis to determine, for instance, the presence or proportion of components or impurities in many substances.

Analytical Methods

Analytical methods are based on the testing of the material in question against the background of knowledge of the subject. To show, for instance, that the sulfate ion is present in a solution, barium chloride can be added. The resulting precipitate indicates that it is there, because barium sulfate, which is insoluble, is always produced in these circumstances. The corpus of knowledge of the chemistry of barium and its compounds is the basis of confidence in the results. A similar dependence on totally consistent and reproducible results is the basis of other analytical techniques of far greater complexity. By these methods, qualitative and quantitative analyses of many materials are carried out.

Such scientific analyses are of value in many fields, one of which is the investigation of crime and other matters of concern in courts of law. Forensic science employs many analytical techniques to identify, measure, and compare. The identification and measurement of drugs and alcohol employ relatively conventional methods similar to those used in other fields of qualitative and quantitative chemical analysis. Comparison is important in many fields of crime investigation. Traces of blood, glass, paint, and fibers are left at scenes of crime or are transferred from the scene to the culprit. Similarly, marks made by tools, fingers, or shoes of the attacker can be found at a scene. It is of importance to show whether the traces or marks match their possible origin and, if they do, how likely it is that they could have come from a different source. Similarly, identification and comparison are essential in the forensic examination of documents.

Since the publication of the first edition of this book, there has been increasing pressure on all forensic scientists to be able to demonstrate the reliability of their analyses and justify their opinion, and questioned document examiners are no exception. Risinger, Saks, and Denbeaux wrote several papers publicly criticizing the discipline for a lack of standards, lack of consistency, and absence of external quality control procedures, equating handwriting comparison to witchcraft.2,3 Since that time, efforts have been made to improve the situation. Regulators both here in the UK and in the United States have required detailed standard operating procedures and standards to be written. In the United States, the American Society for Testing and Materials (ASTM) has published a series of standards covering a range of forensic sciences,4 including some aspects of document examination, and in Europe, the European Network of Forensic Sciences (ENFSI) established working groups in various disciplines that are responsible for developing and maintaining standards. Two of relevance to questioned document examiners are European Network of Forensic Handwriting Experts (ENFHEX) (handwriting) and European Document Examiners Working Group (EDEWG) (other aspects of document examination), and both have written standards on a number of processes. Independent Australian researchers led by Found and Rogers have instigated quality assurance tests to establish the expertise of handwriting and signature comparison,5 and most major laboratories in the United Kingdom have to acquire ISO 17025, independently assessed by the UK Accreditation Service (UKAS) before they can practice in the criminal justice sector. As a consequence, there has been a continuous improvement in the standards associated with document examination over recent years. While none of this can accredit a specific opinion—people can still make mistakes—it gives individuals and organizations a track record that can be inspected; one no longer has to rely solely on the reputation of an individual, and longevity is no longer a measure of expertise.

Documents

A convenient definition of a “document” is a physical item that contains written or printed information. Much information can now be stored electronically, and this is outside the scope of this book. At first it might be considered that there is little requirement for a forensic document examiner in the modern electronic age—the day of the paperless office, the cloud, virtual accounts, and encrypted information shared on multiple electronic devices is here, and there much less reliance on the printed contract, handwritten check, or authenticated signature than there used to be. However, walk into any modern office and the myth is soon dispelled; sticky notes on computers, lists, reference numbers, printed emails, and photocopies are all documents that could be relevant to an investigation. The scope and variety may be broader, but the general principles remain. Documents considered in this book are those normally made of paper, but other materials, including boards, walls, or even bodies, can bear written messages.

The information contained in a document can be considered as occurring at two levels: the superficial, where what is conveyed by the document is expressed in writing, typewriting, or printing, or a combination of any of these, and at a deeper level, where other, less obvious, evidence can be found. It is in the latter field, which is the province of the document examiner, where information about the identity of the writer, the source of the typewriting or printing, the presence of traces of erased entries, and many other factors can be discovered. The significance of such discoveries can be of interest to many people in different occupations, but it is when documents contain incriminating information that their origins are the concern of investigating police officers and, later, the courts. If a document is not what it seems but once bore different information now removed or altered, the deceit it carries in itself will be of vital interest to a civil or criminal court. It is for these reasons that most scientific examinations of documents are carried out by forensic document examiners, whose conclusions are put before the court as written statements or given orally as expert evidence.

Material properly deduced from a document by comparing it with one or more other documents can provide invaluable evidence on which a judge or jury may reach a decision. A connection between a crime and an individual, or the exclusion of that individual from the investigation, can be established. The principle involved in all of these comparisons is the same as that already referred to in other branches of forensic science: the testing of various parameters and reference to the background knowledge of the subject in order to reach a conclusion. Similarly, information can be adduced from a document by methods other than comparison. By the exploitation of methods that detect more than the eye can see, facts that are of value to an investigator or to a court of law can be obtained.

Thus, the scientific method is now established as the correct and proper way of evaluating such evidence provided by documents. It is not the only way; there are still practitioners all over the world who use methods that cannot be so described, and many express erroneous opinions through not following basic principles.6 Conclusions are reached and stated with great certainty on insufficient evidence, and the value of proper deduction is underestimated. This is particularly true in the case of handwriting comparison, where “experts” practice without the benefit of proper training or methods, working on instinct and in their own unconventional ways. Most document examiners, however, follow the standard methods outlined here and provide an invaluable service to investigators and courts. The reader should note that there are two types of handwriting examiner—forensic document examiners (FDEs) and graphologists. This book concerns itself with the skills of the former in identifying authorship; graphology is an expertise in its own right, used, for example, to infer a person’s character, but it rarely has a place in criminal investigation. (see “Document Examiners” below for further comment).

In any science, there are areas of uncertainty; the complete knowledge of a subject is never obtainable. In some, especially those allowing accurate measurements to be made, an analysis based on these provides precise results. Much of the work of the document examiner falls into the former category. Handwriting comparison does not, at present, permit exactly reproducible calculations of likelihood, although attempts have been made to do this.7 While precise measurements are possible, there must still be an element of interpretation based on experience, and consequently, the probability that two writings came from one source cannot be calculated. This is true of most forensic science disciplines (except for DNA databases), and precision should not be confused with accuracy. This means that some degree of subjectivity must be present; without a technique that automatically produces the exact result, any analytical method must depend on the experience and ability of the analyst.

In every analytical method, the limitations must be appreciated. It is erroneous to express any conclusion with a certainty that does not recognize the limitations of the method and the accuracy of the observations on which it is based. However, although these limitations exist, conclusions can be properly drawn if these limitations are recognized; the danger of wrong results occurs when they are not.7

In handwriting comparisons, proper account must be taken of complexities such as the variations found in the writing of one person that at first seem to indicate another writer or, conversely, the possibility of accidental coincidence of a ...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Contents
• Preface
• Acknowledgments
• Authors
• 1. Introduction
• 2. Handwriting: The Variations between Normal Writings
• 3. Handwriting: Accidental and Deliberate Modification
• 4. Handwriting: The Purposes and Principles of Scientific Examination
• 5. Handwriting: The Collection of Samples
• 6. Typewriting and Typescripts
• 7. The Materials of Handwritten Documents: Substances and Techniques
• 8. The Examination of Printed and Photocopied Documents
• 9. Incidental Marks and Other Scientific Examinations
• 10. The Functions of Imaging in Document Examination and Other Special Techniques
• 11. Document Examination in Court
• Index