Module 5 - Polygraph Testing & Forensic Document Analysis

Chromatographic Analysis of a Mock Ransom Note - Solution

Taking a look at the three samples you should be able to see a pattern for each pen:

• Pen A loses its colour fairly consistently from the initial starting point moving upwards.
• Pen B loses very little colour at the bottom, instead it loses most of its colour higher up on the strip
• Pen C loses starts to lose its colour in the middle of the sample and continues to the top of the strip.

Looking closely at the ransom note you can see that it loses some ink at the very bottom, it is particularly noticeable towards the top of the letter 'H'. Then as you look upwards through the rest of the word 'Hand' you can see that the ink is removed farily uniformly. This certainly doesn't look like Pen B or Pen C since they lose most of their colour higher up on the paper. This looks most like Pen A.