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What is Forensic Document Examination?

The term "forensic" means simply, "having to do with the law."  Document Examination, as an established field of scientific study, came into being early in this century as a means of identifying forgery and establishing the authenticity of documents in dispute. It grew out of the need of The Court to be able to correctly evaluate document evidence. It has been stated that "Forgery was practiced from the from the earliest times in every country where writing was the medium of communication" (The Law of Disputed and Forged Documents, J. Newton Baker). It was especially profitable in those earlier times of general public illiteracy. For the reason that most of an examiner's work involves some form of handwriting problem, the field is sometimes referred to as "Handwriting Identification" and the practitioner as a "Handwriting Expert". Albert S. Osborn , with the publication of his book Questioned Documents in 1910, is rightfully credited with laying the foundation of this field of forensic examination.

Definition of a Document

A document may be broadly defined as anything that bears marks, signs, or symbols which have meaning or conveys a message to someone.

Scope of Document Examination

  • Identification of handwriting and signatures
  • Identification of a document as a forgery
  • Identification of typewriters, check writers, and photocopies
  • Detection of alterations, additions, deletions, or substitutions
  • Deciphering alterations and erasures
  • Identification and deciphering of indented writing
  • Comparisons of inks and identification of type of writing instrument

Handwriting Identification 

Handwriting identification is based on the principle that, while handwriting within a language tends to be alike to the degree that we can meaningfully read it, there are individual features that distinguish one person's writing from that of another. Just as no two people are exactly alike, the handwritings of no two people are exactly alike in their combination of characteristics. There are, of course, natural variations within the handwriting of each individual. These variations must be closely and carefully studied by the examiner, so that he can distinguish between what is a "variation" and what is a "difference".

The examiner must also be cognizant of the differences between "class characteristics" and "individual characteristics". Class characteristics are those which are common to a group such as a particular writing system, family grouping, foreign language system, or professional group.  Individual characteristics are those which are personal or peculiar letters or letter combinations, which, taken together, would not occur in the writing of another person.

Handwriting identification is a comparison study requiring authenticated specimens of known handwriting from the individual(s) concerned. These are closely compared to the handwriting characteristics exhibited by the questioned writing in order to determine authorship. Like must be compared to like: printing to printing and cursive to cursive, with comparable letters, letter combinations, words, and numerals.


Below are the classes of forgery commonly encountered:

  • No attempt is made by the forger to imitate the genuine signature of the person purportedly signing the document.
  • There is an attempt to imitate the genuine signature by some method of tracing of a model signature.
  • There is a freehand attempt to simulate the genuine signature from a model.
  • The document and the purported signer are fictitious.
  • A "cut & paste" job wherein a genuine signature, or copy thereof, is transferred from some authentic source to a fraudulent document.

Other disputed signatures include those which are genuine but which were disguised, or written in some illegible manner, by the writer for the purpose of later deniability; and signatures which, though genuine, the author either has no memory of executing or is unwilling to accept as genuine.

It is possible for the document examiner to identify a document or signature as a forgery, but it is much less common for the examiner to identify the forger. This is due to the nature of handwriting in that, while the forger is attempting to imitate the writing habit of another person, the forger is, at the same time, suppressing his own writing habit, thereby disguising his own writing.

In attempting to either disguise one's own writing or imitate that of another, the briefer the body of writing the easier it is to continue the disguise. As the writing becomes more extended, the greater the probability that one's own subconscious habit will intrude itself into the disguise attempt.

There are no reliable methods of predicting from the writing whether the author was male or female, or right-handed or left-handed.

Identification of Typewriters and Checkwriters

With regard to typewriters, questions arise as to whether a series of documents were prepared on the same typewriter; what make/model of typewriter was used; or when was the typed document produced?

Typewriters are identifiable as to make and model by means of class characteristics such as manual/electric, fabric ribbon/carbon film ribbon, typebars/daisywheel/ball element, typeface design, and so on. Machines may acquire individualizing characteristics to varying degrees due to use or misuse, damage, and general wear. The degree of success in a given case will vary with the type of machine with which the examiner is faced.

Check writers, also known as check protectors, may be identified as to manufacturer by its mechanism and typeface design, and individualized by accidental characteristics resulting from damage and wear and tear.

Identification of Indented Writing

Indented writing is an imprint which may be left on the underlying pages when the top sheet of paper is written upon. This impression of the writing is influenced by pen pressure and thickness of the paper. Indented writing is very useful as a form of connecting evidence, such as tying a robbery note to a writing pad recovered from a suspect. Classically, indented writing was identified and deciphered by means of low angle oblique light and photography. More recently, an instrument known as an Electrostatic Detection Apparatus, or ESDA, is now used to produce a visual image of the indented writing on transparency film. This procedure is non-destructive, and rather non-detectable.

Detection and Decipherment of Obliterations and Alterations:

These examinations are performed in order to detect whether a portion of a document has been altered, some portion rendered not readily visible, or some text added. If an obliteration/alteration is identified, then the method is determined and described, and if possible the text of the obliterated entry deciphered. Instruments such as a Video Spectral Comparator (VSC) assist in this study. The VSC allows the examiner to examine the document through infrared illumination using an infrared sensitive CCD camera as a detector. The image is examined by viewing on a monitor, and digital image processing through a computer. This is very useful in ink differentiation.

Qualifications of a Forensic Document Examiner

A Forensic Document Examiner must have a sound basic education through the baccalaureate degree. The typical training period is two years of study and practical experience in an established questioned documents laboratory where the examiner trainee studies the basic literature, completes study projects, becomes familiar with the role of forensic sciences in general and questioned documents in particular as they relate to the legal system.

It should be understood that questioned documents is a valid and legitimate field of study as a discipline in forensic examinations and identification. It is not to be confused with "graphologists" or "grapho-analysts" who claim the ability to assess personality traits of a person from their handwriting. Whether the claim is valid or not, the association of these individuals with handwriting has caused some of them to claim sufficient expertise to determine whether or not a signature is genuine.