AGI Will Detect If You Forged Your Spouse’s Signature

October 16, 2017

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A discipline in forensic sciences which concerns in evaluating documents which are disputed in the legal system. The main goal of forensic questioned document experts is to examine the characteristics of a document and to determine if a document is authentic or altered based on scientific interpretation and reasoning. 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 Ink analysis is done to differentiate different alleged ink entries. It can be destructively done by using Thin Layer Chromatography (TLC) technique or non-destructively using Video Spectral Comparator (VSC). Different ink entries have different luminescence property and hence behave differently under light source of different wavelength.

Figure 1A: Pen streak made using "Papermate Fine Blue" ballpoint pen luminescent under spotlight in a range of 485 to 610 nm wavelength. — Figure 1A: Pen streak made using “Papermate Fine Blue” ballpoint pen luminescent under spotlight in a range of 485 to 610 nm wavelength.

Figure 1B: Pen streak made using "Papermate Kilometrico 100" ballpoint pen do not luminescent under spotlight in a range of 485 to 610 nm wavelength. — Figure 1B: Pen streak made using “Papermate Kilometrico 100” ballpoint pen do not luminescent under spotlight in a range of 485 to 610 nm wavelength.

The table above shows that two (2) different ink entries on the same document shows different luminescent behaviour under the same lighting condition, although they appear similar to the naked eye.

Documents can be examined microscopically to observe the nature of ink dispersion on its printed or written surface.

Inks from different types of pen (ballpoint pen, gen pen, fountain pen or roller pen) or printed using different techniques (laser, inkjet, letterpress, lithography and etc.) possess different characteristic when viewed under microscope.

Figure 2A: Handwriting written using a gel pen.

Figure 2B: Handwriting written using a ballpoint pen.

Handwriting written using a gel pen looks more diffused that the handwriting written using a ballpoint pen when observed under microscope. Halo and striation is only visible in ballpoint pen due to the viscosity of the ink.

Questioned signatures and questioned handwritings will be authenticated by comparing to genuine reference handwriting or signatures.

This will be done by thorough visual observation of specific attributes which are individualistic to the author to establish conclusion.

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