Abstract
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) chemical mapping was used to investigate the order of deposition of natural latent fingerprints and laser printed ink on paper. This feasibility study shows that sodium, potassium and C3H5 positive ions were particularly abundant endogenous components of the natural fingerprints and also present in the paper examined, but were mostly absent in the laser printed ink. Mapping of these ions enables the observation of friction ridges from latent prints on the ink surface, only when a fingerprint was deposited above the layer of ink. As a demonstration of proof of concept, blind testing of 21 samples from three donors resulted in a 100% success rate. The sensitivity of this technique was investigated within this trial through the examination of up to fifth depletion fingerprints and ageing of up to 28days. Migration of fingerprint and paper components to the ink surface, although observed with increased ageing time, was not found to compromise determination of the deposition sequence.
Original language | English |
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Pages (from-to) | 2-7 |
Number of pages | 6 |
Journal | Science and Justice |
Volume | 53 |
Issue number | 1 |
Early online date | 2 Jul 2012 |
DOIs | |
Publication status | Published - Mar 2013 |
Externally published | Yes |
Keywords
- Time-of-flight secondary ion mass spectrometry (ToF-SIMS)
- Fingerprints
- Laser printing
- Paper
- Questioned documents
- Forensic sciences