There are numerous pre-existing fingerprint development techniques, however, often prints are difficult to develop, depending on their age or the surface upon which they have been deposited. Forensic scientists are relentlessly looking for new and better methods to enhance fingerprints. More recent technologies have higher sensitivity to very low levels of constituents present in residues and so are able to unearth significant details from a person's fingerprints at molecular level e.g. DNA, drug metabolites. Therefore, research continues in an attempt to generate novel, nondestructive processes that can enhance latent fingerprints. Exposing fingerprints to the p-block compounds selenium dioxide (SeO2), phosphorus sulfides (P4Sx) and phosphonitrilic chloride trimer (NPCl2)3, in the vapour phase resulted in latent prints being visualized on a range of media. Selenium dioxide revealed prints on metal surfaces (e.g. brass) which were enhanced further upon formation of a dark brown coating of copper-selenide formed on the surface when exposed to moisture, giving a better contrast. P4S3 vapour revealed a higher percentage of prints and samples had greater stability in air while although (NPCl2)3 was able to develop fingerprints, the low quality was undesirable. Initially it was thought that (NPCl2)3 has the potential for further derivatisation but was proven very difficult to interact with compounds especially those with the potential to induce fluorescence. However, all three compounds are commercially available and sublimation techniques are straightforward.
Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:747869 |
Date | January 2013 |
Creators | Shah, Bansi C. |
Publisher | Loughborough University |
Source Sets | Ethos UK |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Source | https://dspace.lboro.ac.uk/2134/12533 |
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