Most people learn to write by imitating a certain style, usually the Palmer or Zaner-Blosser method, but eventually idiosyncrasies develop in the way letters are formed that come from factors like education, artistic ability, physiological development, and preference. That's what makes handwriting distinct and personal. In fact, experts say that no two people write alike. Repeated usage over a long period of time crystallizes a specific style that will show only slight variation, if any, over the years.
Handwriting experts study the variations in writing samples to try to determine if two (or more) different documents were written by the same person and thereby to identify the known author of one sample with the known author of a similar one. The same odd characteristics ways of spelling a word, the particular slant or spacing, or manner of forming certain letters are expected to show up across samples by the same person, and they're evident even when the person may be trying to conceal his or her identity.
Although handwriting analysis suffers from being compared to the pseudo-science of graphology, in fact it is strongly peer-reviewed and certified by forensic groups such as the American Society of Questioned Document Examiners.
Analysts look at the following features: class characteristics, formed from the writing system learned, and individual characteristics, or features that are not common to any group.
It is the latter that play the most important part in forensic investigation. A known specimen written by an identified person is called the "standard" or "exemplar," and it should be as similar as possible to the questioned writing, specifically containing similar words or letter combinations. The more samples available of both types, the better. The primary factors for analysis are divided into four categories:
- Form refers to the elements that comprise the shape of the letters, proportion, slant, angles, lines, retracing, connections, and curves
- Line Quality refers to the results from the type of writing instrument used, and the pressure exerted, along with the flow and continuity of the script
- Arrangement involves the spacing, alignment, formatting, and distinctive punctuation
- Content this is the spelling, phrasing, punctuation, and grammar
In some cases, aspects of the handwriting will be quite unique, which gives them a lot of weight for evidential value. If there are significant dissimilarities between an exemplar and a questioned document, then it's likely that there are two different authors, unless the differences can be accounted for. However, similarities are not necessarily a sure indication, since even the most unique factor in a person's handwriting may show up in someone else's. Expert handwriting analysis involves taking into account a wide variety of factors and a repetition of similarities.
Problems can occur when the writing has been deliberately disguised, such as in threatening or taunting letters. However, the form may change, but the type of words used and the sources that have influenced phrasing remain the same.
It may also be difficult to detect an expert forgery, such as when Clifford Irving forged the letters of the reclusive Howard Hughes to get a publishing contract for Hughes' life story. He was unmasked partly by an announcement from
Hughes himself and partly by the analysis made by a document examiner in the U. S. Postal Service. The identification of Irving's style lay in the form of certain letters and the manner in which certain strokes ended evident despite the extremely close likeness to Hughes' known signatures.
Writing habits that are altered with drugs, alcohol, or other factors may also make identification troublesome.
There are no clear-cut rules or formulas to follow, so expertise develops from years of exposure. Today there are many automated techniques for making an analysis, such as FISH, or the Forensic Information System for Handwriting, but there are cases in which careful and experienced interpretation is necessary.
In the case of a document written on a typewriter (although many these days are written on computers that fail to have the same machine-specific idiosyncrasies), a different method for comparison is used. Part of that involves attempting to identify the make and model of the typewriter used for a QD, and part involves identifying a suspect machine. Usually the specific identification factors derive from typeface defects, mechanical failures, or damage. Examination of the ribbon may also be helpful. Again, identification is a matter of comparing known writings from the machine with the questioned document.
The goal is to collect samples that have been written within two or three years of the questioned document, and critical to a successful identification is the adequate collection of samples. Known exemplars are the primary source, but if they are not sufficient in number, then the suspected author may have to be asked to sit down and write and that has its own protocol. Handwriting samples lie outside the protection of the Fifth Amendment and therefore can be acquired for a criminal case without constitutional violation of privacy.
If someone is asked to provide handwriting samples, the procedure is to sit him or her at a table where there will be no distraction, keeping in mind the following:
- The subject ought not to be shown the questioned document
- The subject is not to be told how to spell certain words or use certain punctuation
- The subject should use materials similar to those of the document
- The dictated text should match some parts of the document
- The dictation should be repeated at least three times
- The subject should be asked to sign the text
- Make sure an objective witness observes the procedure
In other cases, whenever there are attempts to alter a document, the paper's surface generally shows the erasure, sandpapering, or razoring that has been applied. Any alteration made with a different color of ink will be detected by infrared lighting techniques. Infrared can also sometimes bring out the contents of a document that has been damaged by fire.
In addition, sometimes a questioned document is merely the indentation on a tablet left by writing on the top sheet, which has been removed. The paper must be studied under oblique lighting or processed with toner powder and an electrostatic charge to accurately see and duplicate the impressions. Where the tablet is found may also help to identify the document's author.
The first time that the method of handwriting analysis played a major forensic role in American history was in the trial of Bruno Hauptmann for the kidnapping and murder of the son of world-famous aviator, Charles Lindbergh. While it's clear that the manner of collecting known samples was improper, and the handling of evidence (and of the defendant) makes the interpretations somewhat questionable, it's also clear that having a large number of comparison samples can significantly contribute to getting a conviction. Let's have a look.