Metal deposition techniques for the detection and enhancement of latent fingerprints on semi-porous surfaces

Jones, NC

Metal deposition techniques for the detection and enhancement of latent fingerprints on semi-porous surfaces

Jones, NC

Permalink

Publication Type:: Thesis
Issue Date:: 2002

Open Access

Copyright Clearance Process

Recently Added
In Progress
Open Access

This item is open access.

Adobe PDF

Download contents and abstractAdobe PDF (998.62 kB)

Adobe PDF

Download thesisAdobe PDF (12.08 MB)

View statistics

Full metadata record

Field	Value	Language
dc.contributor.author	Jones, NC
dc.date.accessioned	2010-03-31T03:48:46Z
dc.date.accessioned	2012-12-15T03:52:38Z
dc.date.available	2010-03-31T03:48:46Z
dc.date.available	2012-12-15T03:52:38Z
dc.date.issued	2002
dc.identifier.uri	http://hdl.handle.net/10453/20188
dc.description	University of Technology, Sydney. Faculty of Science.	en
dc.description.abstract	Fingerprints can provide critical evidence in the investigation of crime. Most fingerprints are latent, or invisible, and hence need detection and enhancement before they can be used in the investigation of crime. While techniques exist for fingerprint development on a range of surfaces, the detection of prints on semi-porous substrates is particularly difficult. Vacuum metal deposition (VMO) and multi-metal deposition (MMO) were investigated for their ability to detect latent prints on such surfaces. VMD is recognised as a very sensitive method of latent print visualisation but inconsistent resu1ts are commonly encountered. This research shows that reproducible VMD development is only obtainable when the amount of gold deposited is carefully controlled. The type and quality of VMD development obtained is influenced by a number of critical factors. These factors include the amount of gold deposited, the polymer type of the surface being treated, the nature of the latent print itself, and the presence of any other contaminants on the surface (whether due to the history of the exhibit or treatment with other fingerprint reagents). MMD has not found routine application due to its complexity and mediocre results. Recent research that sought to overcome these problems resulted in the development of a new formulation known as MMDII. Several MMD formulations were trialled in this study and MMDII proved to be the superior formulation, giving better overall print detail. On non-porous surfaces, MMDII may offer further print development than that achieved with cyanoacrylate fuming (CAF) and luminescent staining, but VMD always gave superior results to MMD. Polymer banknotes are a difficult semi-porous surface, causing particular problems for fingerprint laboratories. A procedure utilising CAF followed by VMD and finally luminescent staining enables successful print development on this substrate. Success on new notes was achieved with prints up to 18 months old; unfortunately, the possibility of successful print development decreases on used banknotes. VMD has two important advantages for print visualisation on polymer notes: i) it is sensitive enough to detect the small amounts of residue remaining; and, ii) the zinc layer removes a significant amount of interference caused by the banknote design. MMD and VMD were compared to standard techniques on other semi-porous surfaces. MMD proved to be the technique of choice on these surfaces. The ability of MMD to react with print residue within and on the surface is believed to be important to its success.	en
dc.format	Thesis (PhD)	en
dc.language.iso	en	en
dc.relation	https://opus.lib.uts.edu.au/bitstream/10453/20188/10/02whole.pdf
dc.relation.replaces	http://hdl.handle.net/2100/1026
dc.rights	info:eu-repo/semantics/openAccess
dc.rights	The author owns the copyright in this thesis including all reproduction and reuse rights for the work. The work may not be altered without the permission of the copyright owner. Attribution is essential when quoting or paraphrasing from this thesis.
dc.rights	au.edu.uts.lib/ppc
dc.title	Metal deposition techniques for the detection and enhancement of latent fingerprints on semi-porous surfaces	en
dc.type	Thesis
utslib.copyright.status	open_access

Abstract:

Fingerprints can provide critical evidence in the investigation of crime. Most fingerprints are latent, or invisible, and hence need detection and enhancement before they can be used in the investigation of crime. While techniques exist for fingerprint development on a range of surfaces, the detection of prints on semi-porous substrates is particularly difficult. Vacuum metal deposition (VMO) and multi-metal deposition (MMO) were investigated for their ability to detect latent prints on such surfaces. VMD is recognised as a very sensitive method of latent print visualisation but inconsistent resu1ts are commonly encountered. This research shows that reproducible VMD development is only obtainable when the amount of gold deposited is carefully controlled. The type and quality of VMD development obtained is influenced by a number of critical factors. These factors include the amount of gold deposited, the polymer type of the surface being treated, the nature of the latent print itself, and the presence of any other contaminants on the surface (whether due to the history of the exhibit or treatment with other fingerprint reagents). MMD has not found routine application due to its complexity and mediocre results. Recent research that sought to overcome these problems resulted in the development of a new formulation known as MMDII. Several MMD formulations were trialled in this study and MMDII proved to be the superior formulation, giving better overall print detail. On non-porous surfaces, MMDII may offer further print development than that achieved with cyanoacrylate fuming (CAF) and luminescent staining, but VMD always gave superior results to MMD. Polymer banknotes are a difficult semi-porous surface, causing particular problems for fingerprint laboratories. A procedure utilising CAF followed by VMD and finally luminescent staining enables successful print development on this substrate. Success on new notes was achieved with prints up to 18 months old; unfortunately, the possibility of successful print development decreases on used banknotes. VMD has two important advantages for print visualisation on polymer notes: i) it is sensitive enough to detect the small amounts of residue remaining; and, ii) the zinc layer removes a significant amount of interference caused by the banknote design. MMD and VMD were compared to standard techniques on other semi-porous surfaces. MMD proved to be the technique of choice on these surfaces. The ability of MMD to react with print residue within and on the surface is believed to be important to its success.

Please use this identifier to cite or link to this item:

http://hdl.handle.net/10453/20188