July 23, 2018

Some years ago I was told the story that shortly after World War 2 a safe-cracker managed to obtain a set of Winston Churchill’s fingerprints, which he had moulded into surgical gloves in the appropriate places.

In order to overcome the problem of the absence of moisture he would rub his gloved hands over his sweating brow before proceeding with his skullduggery.

The latent prints picked up at crime scenes probably created a degree of humorous confusion for the investigating officers.

On the assumption that the story was in fact based on actual events, would it have been possible to successfully carry out such a subterfuge?

Bearing in mind all the intricacies and safeguards involved in fingerprinting analysis, the answer is probably no.

Furthermore if it becomes possible to use the amino acids found in the sweat to arrive at a DNA profile of the owner; this would further support the fingerprinting expert’s findings.

The matching of bullets with weapons has, with the availability of sophisticated digital photographic equipment and comparison microscopes, become almost infallible, making forensic ballistics an even more powerful investigative tool.

Forensic examination of questioned documents where human involvement, and a much higher degree of subjectivity play a greater role is still the orphan among all the other forensic disciplines. It is also probably the most required, particularly in civil litigation.

During its heyday the matching of typescript with a lever type typewriter was not a particularly difficult exercise. Although the type styles produced by the individual typewriter manufacturers were for the most part either pica or elite there was a high degree of individuality in the composition of the striking type-head. Furthermore wear and tear usually produced obvious and subtle identifiable features, particularly among worn or damaged serifs.

The introduction of the interchangeable golf ball and daisy wheel made positive identification a little more difficult, and the emphasis of investigation had to be shifted more to the role of the typist. Preferred margin justification, phrasing, punctuation, general composition, and style, often became the give-away connection features.

With the advent of the word processor and, later, the personal computer, the range of typestyle-font variation has expanded, and today it runs into many thousands, making the matching of typescripts with a specific printer extremely difficult. There are, for example, many versions of New Times Roman – the differences between them are so very subtle that they can easily go undetected. Furthermore changing the font within a word or sentence can be done with ease, even by a novice.

Periodically the manufacturers of software upgrade their systems by including new facilities, for example in Windows 97, Microsoft introduced ordinal number symbols that slot involuntarily in the date; the ‘th’ of day fifteenth of December, is automatically changed into the diminutive form of 15th of December. This is of importance when this type of symbol appears in a questioned document dated long before the facility was introduced.

Cut-and-paste manipulation has been a common form of fraud since the early days of the photocopier. Today with even a simple graphics program a signature can be placed accurately onto a document without leaving any tell tale traces. However, the obstacle of the third dimension i.e. pressure, is still an unsolved difficulty for the would be fraudster.

In many instances where ink analysis is necessary, a non-destructive Video Spectral Comparator can be used to reveal latent details in the writings that appear outside the range of the visual spectrum.

With all the modern technology, the signature, which has stood the test of time, still remains probably the safest proof of identity. But how safe is it?

Forgery is often spoken of and yet in fact there are very few forgeries that cannot be detected by an experienced examiner. For the most part a forgery is either a tracing or a freehand-simulated signature.

The former requires a model, transmitted light, and a steady hand. Usually the biggest flaw in this form of forgery is the line quality, which includes the evenness of the line and the pressure pattern, that is difficult to produce spontaneously, and at the speed and with the familiarity at which the victim writes.

In freehand-simulated forgery, the principle requirement is practice. Probably the best exponents of this type of forgery are schoolchildren who practice their mother’s signature in order to confirm to their teachers that the homework assigned to them was done.

As one’s signature is linked to habit, the forger must be aware of his victim’s writing habits, such as baseline alignment and the proportional height of tall and short letters etc. At the same time he must be careful to omit any of his own habits, which would become give/away alien features in the masterpieces.

There are three main issues that must be addressed by the examiner in order to determine authenticity.

  • From the outset the examiner must be convinced that the forger has at least the same level of writing skills as that of the victim. Obviously the forger with lesser writing skills of the victim cannot hope to produce a convincing forgery.
  • He/She must have as many contemporaneous acknowledged signatures available as standards for comparison purposes, preferably written under similar circumstances, and on similar documents that bracket the date on which it purports to have been written. Apart from anything else, this would be necessary in order to determine the range and the degree of natural variation that occur in the victim’s signature.
  • And the hardest part, he must be able to recognize the difference between natural variation and divergence.

The electronic signature is gradually being introduced, and no doubt it will feature more in the years to come.

During the years, and right up to the present day, disastrous errors have occurred because of incorrect assessments made by so-called handwriting experts. Today, in many courts of law throughout the world, such evidence is treated with a great deal of suspicion and even contempt. The process of law is complicated enough, and the meddlesome involvement of incompetent and dishonest expert witnesses only adds to litigation problems and often results in misery for innocent people. (One such case that comes to mind is the infamous Dreyfus treason trial.

For questioned document examiners to maintain any credibility, they must not view themselves as advocates for either of the litigants but rather as advocates for the truth.

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