An Amino Acid Model for Latent Fingerprints on Porous Surfaces*


  • Lothar Schwarz Dr.Phil.Nat.

    1. KT 41-2 Research, Development and Testing of Fingerprint Detection Methods, Kriminaltechnisches Institut des Bundeskriminalamts, 65173 Wiesbaden, Germany.
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  • *

    Presented partially at the 6th Biennial Meeting of the International Fingerprint Research Group in Canberra, Australia, March 27, 2007 and at the International Symposium on Advances in Fingerprint Identification, Punjabi University in Patiala, India, Feb. 10, 2008.

Additional information—reprints not available from author:
Lothar Schwarz, Dr.Phil.Nat.
Bundeskriminalamt, KT 41
65173 Wiesbaden


Abstract:  Analytical standards are needed in latent fingerprint detection for research and development as well as for quality control in routine work because normal fingerprints are too varied for comparison studies and tests. One way is to create latent fingerprints. For the amino acid sensitive detection method this can be achieved by coating test items with an amino acid solution using a modified commercial office bubble jet printer. Besides low costs, fast and easy preparation, the main advantage of a bubble jet printer is that the amino acid loading per area on the test item can be calculated by weighing the cartridge on a balance. This opens the possibility to determine the deviation for every printing series. The reproducibility of prints in a printing series made by one cartridge has a deviation of 2–16% and of prints made by different cartridges 20–25%.