Handwriting identification relies on the principle that
Handwriting identification relies on the principle that there are individual characteristics that distinguish a person’s handwriting from that of another person. There are no two people in the world, who have the same handwriting just like fingerprints. Handwriting identification is based on the following concepts.
One, there are no two people who have the same writing manner. Two although a person’s handwriting varies, there is habitual features that appear in his or her handwriting and lastly the characteristics that are used to identify each persons’ handwriting vary to a lesser extent than the same characteristics in samples written by other people (Saferstein, 2010).
The differences in handwritings have made handwriting identification important in the modern world. Handwriting identification is a comparison study that tries to establish the writing in question was done by a specific person through comparison with other texts or samples.
In handwriting identification the aspect of variation in handwriting that are considered include; size of the letters, consistency or lack of it while writing, proximity of the letters to the base line, pressure applied while writing, alignment, and the writing instrument used (Mansikki, 2003).
How a forensic document examiner analyzes evidence from a photocopier, fax machine, printer, and typewriter
The application of various sciences in law is referred to as forensic science. Forensic document examination is the application of allied sciences and analytical techniques to investigate documents. The examination of documents involves analysis and comparison of photocopies, handwriting, typewriting, printing, inks, and other materials in order to establish originality of the materials and detect any alterations.
Forensic document examiners may be asked to determine the machine or equipment that was use to produce a document. They may also be asked to establish the specific printer, photocopier, fax, or typewriter that was used to make the document. When examining documents written by a typewriter an examiner tries to look at several things. One, different typewriters are known to cut letters differently. The examiner may also look at the date on the paper and see if it is consistent with the age of the ribbon used in the typewriter.
Faxed documents are reduced slightly in size and the line quality is bad. In older models, the faxed document diagonal lines have jagged edges. When a forensic document examiner is investigating these documents, it is important to look at the original document to make comparisons and detect any alterations made. It is also important to look at the TTI (Transmit Terminal Identification) and the RTI (Receiving Terminal Identifier) to see if the document that are in question are authentic (Koppenhaver, 2007).
Photocopiers leaves trash marks on the copies made. These trash marks are caused by nicks on the drum and dirt on the glass. A forensic document examiner will seek to see if the trash marks on the paper will be consistent with the ones made on the sample he is trying to seek authenticity. Because of slippage when the paper goes through the photocopier the location of the marks may vary slightly but the marks from each page will align properly (Koppenhaver, 2007).
Color printers and photocopiers work by applying multi color and ink on to a paper or any other supporting medium. Many of these machines will form a repeated sequence of inconspicuous yellow dots on the entire surface of the paper or document. These yellow dots are inconspicuous to the eye, but can be seen in the non-printed part of the document when shone with ultraviolet light.
Where the relationship and location of the dot relative to the next indicates the serial number of the machine and the date and time the document or paper was made. Forensic document examiners look at these characteristics to make their conclusion about the machine and authenticity of the document (Koppenhaver, 2007).
Huber, R. A. & Headrick, A. M. (1999). Handwriting identification: facts and fundamentals. Boca Raton, Fla.: CRC Press
Koppenhaver, K. (2007). Forensic document examination: principles and practice. Totowa, N.J.: Humana Press.
Mansikki, P. (2003). Handwriting Identification. Retrieved From http://www.forgeryfinder.com/Hand.htm
Saferstein, R. (2010). Criminalistics: An Introduction to Forensic Science. Upper Saddle River, NJ : Prentice Hall.