Document analysis
Document analysis is a forensic discipline focused on determining the authenticity and legitimacy of various types of documents, which include handwritten notes, printed material, and computer-generated documents. This area of study is crucial in legal contexts, both criminal and civil, to ascertain the validity of evidence presented in court. Analysts utilize a range of investigative methods, such as handwriting and signature verification, typewriter identification, and ink examinations, to detect forgeries or alterations. Each writing sample is compared to known genuine examples to identify distinguishing features that indicate authenticity or forgery.
As technology evolves, document analysis has adapted to include assessments of digital documents, but the reliance on traditional paper documents remains significant. Analysts are trained to recognize the individual characteristics that emerge from repeated use of writing instruments and printing machines, which can aid in identifying the source of a document. Furthermore, they employ techniques like infrared photography and chemical analysis to uncover alterations or verify the age of inks and papers. This field continues to expand in importance, reflecting the ongoing need for skilled experts to navigate the complexities of document verification across various mediums.
Document analysis
SIGNIFICANCE: Determining the authenticity of documents is important in the fields of both criminal law and civil law. Modern document analysis now encompasses computer documents, but even in the twenty-first century’s increasingly paperless world, people and institutions continue to rely heavily on handwritten and printed documents, and the need for trained document analysts is continuing to grow.
Document analysis is a diversified area of forensics that encompasses a wide spectrum of methods of investigation. In trying to determine whether documents are legitimate, examiners employ such techniques as handwriting and signature identification; typewriter, computer, fax, and copier identification; pencil lead and ink examinations; and paper analysis. The field was pioneered by Albert S. Osborn, whose 1910 book, Questioned Documents, was the first major work in the field; it is still considered an important and useful work.
Handwriting and signature identification is used in the examination of such documents as letters, checks, wills, ransom notes, and suicide notes. During the Lindbergh baby kidnapping and murder trial of 1935, Osborn testified that the writing on the ransom notes was consistent with the handwriting of the defendant Bruno Hauptmann, who was convicted and later executed.
Handwriting and Signature Identification
Generally, the genuineness of any writing is established by comparing the writing on suspect documents with handwriting samples known to have been written by the purported signers of the suspect documents. Examiners prefer to have a variety of authentic writing samples to use for comparisons. Since the handwriting of individual writers tends to vary with the circumstances in which they are writing, document examiners need authentic samples that have been written under a variety of circumstances.
A skilled forger may succeed in faithfully copying a number of aspects of another person’s handwriting; however, there are always noticeable differences between authentic and forged writing specimens. For example, forgeries often differ from authentic specimens in the speed with which they are written and the pressure that the forgers apply to their writing instruments. Even when there is a successful mimicry of speed and pressure, it is almost impossible for forgers to remove all traces of the peculiarities of their own writing from their forgeries.
Typed, Printed, and Copied Documents
Document examiners must sometimes question whether suspect documents originated from particular machines. Unlike human handwriting, which has numerous individual characteristics, brand-new printing devices are generally very much alike and possess only the class characteristics that make new machines of the same models produce nearly identical documents. However, after machines are used repeatedly, they begin to develop individual characteristics, the same way that shoes develop individual characteristics with increased wear. Examiners focus on these individual differences.
Manually powered typewriters were prone to having some letter keys strike their ribbons and paper with less pressure than others, and individual typists using the same machine would not all use the same force on the same keys. Photocopying machines often have imperfections in their glass plates or distribute their toner powder in ways that make them unique. All fax transmissions received by a single machine have unique identifying lines. Computer printers also develop their own individual characteristics over time.
To improve their ability to make correct identifications of typed, printed, and duplicated documents, examiners like to work with at least ten documents from each machine they examine. It is also helpful to obtain the examples as soon as possible after the suspect documents are crated, as the individual characteristics of the machines continue to change over time.
Pencil Lead, Ink, and Paper Analysis
Paper documents can be altered in many ways. They may be erased or obliterated. They may also be overwritten. Attempts may be made to completely destroy documents by burning. Document examiners are often faced the challenge of enhancing or reconstructing writing on documents. Using different light sources is often helpful in this type of work. Unless the inks used to alter documents are the same as the inks originally used on them, they will reveal different chemical and light-reflecting properties to examiners. Document reconstruction and enhancement can be done using infrared photography or digital-image processing.
Inks are especially important to identify when the ages of documents and signatures are in question. Inks are also examined when it appears that something on a document has been altered by simply writing over the document’s original text. For example, forgers may simply add zeros to the dollar amounts written on checks. Ink analysis can also help determine the age of a document or the writing on it. Very old inks are easy to spot because of their chemical compositions, as the manufacture of ink products changed dramatically after 1950. Examiners must also be familiar with computer inks. The chemical compositions of inks can be revealed through the use of thin-layer chromatography.
Papers are analyzed in a variety of ways by examiners, who pay particular attention to the physical characteristics of paper. Watermarks, which are regularly used in U.S. currency, can be examined, and analyses can be conducted on the fibers, chemicals, and trace elements that make up individual papers. Examiners must also be familiar with the types of papers used by computer printers, fax machines, and copiers, as well as standard writing and typing papers.
Bibliography
Allen, Michael. Foundations of Forensic Document Analysis: Theory and Practice. Hoboken: Wiley Blackwell, 2016. Print.
Dines, Jess E. Document Examiner Textbook. Irvine: Pantex International, 1998. Print.
Ellen, David. The Scientific Examination of Documents: Methods and Techniques. 3rd ed. Boca Raton: CRC, 2006. Print.
Herbertson, Gary. Document Examination on the Computer: A Guide for Forensic Document Examiners. Berkeley: Wideline, 2002. Print.
Kovatch, Sophia. "Is It Forensics or Is It Junk Science?" ProPublica, 31 Jan. 2023, www.propublica.org/article/understanding-junk-science-forensics-criminal-justice. Accessed 25 June 2024.
Slyter, Steven A. Forensic Signature Examination. Springfield: C. C. Thomas, 1996. Print.
Songer, Mark. "Forensic Handwriting Analysis." Robson Forensic, 13 Nov. 2023, www.robsonforensic.com/articles/forensic-handwriting-analysis-expert. Accessed 25 June 2024.