Advances in Fingerprint Technology.pdf

The most recent developments in novel approaches to latent print development
involve photoluminescent nanocrystals or nanocomposites by Menzel
and collaborators. 248-250 Practical methods based on this interesting
approach have yet to be fully developed. The subject is reviewed and explored
in Chapter 6.
Miscellaneous Methods
Nolan et al. 251 reported that latent prints developed by small particle reagents
are easily imaged by the back-scattered electron image mode of the scanning
electron microscope (SEM). Low SEM magnifications have permitted the
recording of single complete fingerprints on checks, newsprint, and other
surfaces. In addition, X-ray radiography and infrared microscopy have also
been suggested for the detection of latent fingerprints. 252,253
Graham and Gray described an electronography technique in 1966. 24 A
latent print was first dusted with fine lead powder and subsequently bombarded
with X-rays from high-energy sources; the emissions were then detected by
photographic emulsions. It was reported that that technique has been used
successfully in developing latent print human skin. 24,254 It also worked well on
multicolored surfaces, background interferences being totally eliminated. 255
A few techniques have been proposed that were based on now dated
serological techniques. 256-258 One study 259 looked at a bacteriological technique
for the detection of fingerprints.
Systematic Approaches to Latent Print Processing
There have been hundreds of techniques for the development and visualization
of latent fingerprints reported in the literature. Each of the methods has
its advantages and performed well under certain conditions. The application
of the correct technique for a particular surface or given set of conditions is
extremely important. The application of more than one technique or reagent
for the detection of latent prints can often increase the number of prints
found or improve the quality of those already developed. However, it is
imperative that reagents are applied in a systematic and correct order. Use
of a wrong or inappropriate procedure might actually destroy the latent print
evidence and obviate any chance for visualization by another technique.
Beginning in 1985, several investigators suggested different logical schemes
for the sequential development of latent prints. 260-262 An excellent manual of
fingerprint development technique was published in 1986 that contained various
systematic process charts for developing latent fingerprints. 260 Lennard and
Margot 8,9 conducted detailed studies of the various chemical reagents available