Acquisition of Sebaceous Fingerprint Topology Using Columnar Thin Films (CTF) on Forensically Relevant Substrates
Fri, 01/24/2014 - 10:24am
The purpose of this research project was to expand on successfully completed proof-of-concept experiments by determining the scientific basis and application of columnar thin films (CTFs) to capture friction ridge detail found in latent fingerprints on nonporous, forensically relevant textured substrates and to compare CTF development of fingerprints with commonly employed fingerprint development techniques.
The authors designed a system, using three sequential computer programs that assess the percentage of the developed fingerprint having definitive minutiae, to objectively assess the quality of each developed fingerprint and identify which development — CTF or traditional — gives the better result. The authors established the critical CTF deposition parameters for developing sebaceous fingerprints and the optimal CTF thickness for different substrates and their evaporants. Results clearly demonstrated the development of friction ridge detail to the pore level using CTFs. This research demonstrated that CFT development of fingerprints on nonporous, forensically relevant substrates not ideal for traditional fingerprint techniques gives superior or equal results for all of the substrates studied except for masking tape, stainless steel, white ABS (plastic), and black nylon. Use of CTFs appears to be particularly suitable for partial bloody fingerprints, for which traditional techniques are ineffective.