This project expanded on successfully completed proof-of-concept experiments by first determining the scientific basis of and the deposition of columnar thin films (CTFs) in order to capture friction-ridge detail on forensically relevant textured substrates; and it compared CTF development of fingerprints with the results of commonly used fingerprint development techniques.
The optimization of CTF development of latent sebaceous fingerprints on nonporous forensically relevant substrate was successful. It is clear that CTF development is a viable technique for developing latent fingerprints on difficult substrates. Although the equipment is still laboratory-based, there is significant applicability to smaller evidence items. Findings also show that for laboratory prepared fingerprints, without concern for sensitivity, the CTF development method is superior to traditional development techniques for some forensically relevant substrates. For others, however, a traditional development technique produced a better outcome. Traditional techniques and CTF were equally good for a few substrates. Researchers also learned that examining and comparing results visually (subjectively) was not appropriate for this research; they needed a method that could assess the quality of developed fingerprints objectively, which enabled an effective comparison of different fingerprint development methods. The method used the FBI’s ULW image manipulation software (GIMP) and a program developed in Mathematica® so as to quantify the minutiae as a percentage. This method has the advantage of assessing both the quality of individual fingerprints and the relative performances of different development methods. Additional research is required before the CTF technique can become a routine law enforcement tool. Specific areas that require further work are suggested. 26 figures, 9 tables, and 30 references
Date Published: June 1, 2013