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different for some lefthanded writers.
Occasionally, a similar effect will occur when the writing is on a sheet of paper.
The presence of an indented shadow line on a piece of paper could suggest the writing
is the result of an indented outline tracing and such an interpretation of the evidence
may be incorrect.
If a photocopy is the subject of the examination by the examiner, it is sometimes
necessary to first determine what copier process was used so he will know how to
interpret the evidence. He also needs to know what effects the copying process will
have on the copied material. Not all inks copy well; for instance, some blue ballpoint
pen inks, when copied, result in very poor images.
The size of the original material may not be the same as the copy. The size and
details of the original information can very significantly from the original depending
upon its location on the page and other factors. Understanding the copying process
and what can happen to the image during it is important for the examiner. If it is
necessary to identify the copier process and copy machine, it may be necessary to
perform a chemical analysis of the toners. The individual doing this work should have
a background in chemistry.
Paper
What is it? What are its properties? Are all papers alike? The study of paper is also a
specialized area and the examiner is not expected to be an expert in paper analysis.
He should, however, have:
• A working knowledge of how paper is made and its properties
• A working knowledge of the different kinds of paper, their uses, and how they
react in different situations and environments
• A working knowledge of writing papers and how they react to writing inks,
erasures, folding, solvents, etc.
The examiner should have a basic knowledge of paper because in his work he may be
asked, for example, to determine the date or period of time when a document or one
of its components was produced or changed.
Mechanical Devices
Documents are created using various mechanical devices such as typewriters, check
writers, computer printers, mimeographs and other duplication machines, plastic
and metal embossing machines, etc. Each machine has characteristics that make it
identifiable. The examiner must know what the characteristics are and how to prop-
erly evaluate their significance when he sees them. This is not an easy task. Consid-
erable time is spent studying and developing skills and techniques necessary to
examine documents produced on any of these or the many other machines that can
be used to make a document.
© 2000 by CRC Press LLC
Hand-Recording Equipment
Machines are not the only devices used to produce markings on documents. Rubber
and steel stamps, seals, authenticating devices, and others are regularly used to
authenticate a document or an entry on the document. Each has its own unique set
of class and individual characteristics that make it identifiable. Rubber and steel
stamps can have dents or chips in the typeface that will produce a void in that
character on the paper or other substance. Seals and cachets may be counterfeit and
placed on the document to give it the appearance of being genuine.
Printing Processes
The types of documents that examiners are now examining require a comprehensive
understanding of printing technology. This is especially true for plastic card docu-
ments such as IDs and payment cards. The use of printed plastic is rapidly becoming
the preferred method of creating financial and identification documents of all types.
In the future, plastic card documents will be a major component of the Forensic
Document Examiner’s work. Paper documents such as personal and business checks
or birth certificates and other counterfeit paper documents are being sent to the
laboratory for analysis with greater frequency.
The characteristics of various printing processes on plastic and paper can be very
different. The examiner must understand printing processes so he can give proper
weight to any characteristics or defects found in the printing he may encounter. The
significance of any defect can be a function of the specific printing method used and
the defects occurring as a result of the printing process. For example, thermal-mass
printing (TMP) is used to print material on specially coated paper and PVC plastic
cards. The examiner should know how it works, what factors affect the printing
process, and how to determine whether the printed material on different cards may
have been done on the same or similar printers.
Types of Examinations Performed
by Forensic Ink Chemists
The Forensic Ink Chemist (FIC) is a specialist in the analysis of ink. Forensic ink
analysis is both a nondestructive and semi-destructive examination made to deter-
mine the physical/chemical profile of the ink. This profile consists of optical and dye/
pigment content properties. Inks analyzed include writing, printing, stamp pad, and
typewriter ribbon inks and photocopy toners. An FIC compares inks to determine
similarities or differences. If a collection of reference standards exists, an FIC can
compare a particular ink against this collection to determine the source (manufacturer
or, in the case of writing inks, the date of first production). Finally, an FIC should be
knowledgeable of, or be able to perform, relative age determination of writing inks.11
Occasionally, a question arises concerning ink entries on documents. The FIC is
most frequently asked to:
© 2000 by CRC Press LLC
• Determine the date an entry or signature was written by a writer
• Determine whether two ink entries were written with ink having the same
formulation
• Determine whether several ink entries were written at or about the same time
Types of Examinations Performed
by the Fingerprint Specialist
Fingerprint characteristics have been used for over 100 years as a reliable means of
identification. A practitioner of this discipline is known as a Fingerprint Specialist
(FS), but this title is misleading. Actually, the FS processes evidence for latent prints [ Pobierz całość w formacie PDF ]