Fingerprint chemistry is complex, with great variability both within and between individuals, and is susceptible to significant changes over time, in different environmental conditions, and between children and adults. Interest in fingerprint chemistry has increased in the last decade primarily due to advances in analytical instrumentation, but despite this increase in research an in-depth understanding is yet to be achieved.
One such analytical technique that has generated significant interest within in this field is Fourier Transform Infrared (FTIR) spectroscopy. FTIR analysis is fast, and requires no sample preparation, but FTIR imaging is particularly attractive to forensic scientists and law enforcement agencies because of its ability to non-destructively analyse a sample for trace amounts of illicit substances. FTIR imaging therefore allows for better continuity of evidence through the forensic chain compared to the more conventional destructive analytical methods such as Gas chromatography/mass spectrometry (GCMS) and matrix-assisted laser desorption ionisation (MALDI). FTIR imaging provides more compelling evidence to a lay jury than GCMS or MALDI, as it does not require interpretation of complex data or dependence upon expert opinion. The identification of any illicit substances in a subjects fingerprints using FTIR imaging demonstrates an unequivocal visual link between the individual, the print and the illicit substance that is far easier for a jury to understand.
This research project will examine the chemical components of latent prints, produce a synthetic biochemical simulant and use this to examine component interactions and, in particular, survivability in response to environmental stimuli.
Sample sizes are sufficient to demonstrate effects if present assuming p<0.05. The primary analytical technique is mico-FTIR imaging which is non-destructive and is used, when necessary, in tandem with GCMS.
Each study is designed following a systematic empirical approach to ensure reliability and reproducibility.
Johnston & Rogers; "The Effect of Moderate Temperatures on Latent Fingerprint Chemistry"; Applied Spectroscopy; Vol 71, Issue 9, 2017 Johnston & Rogers; "A study of the intermolecular interactions of lipid componentsfrom analogue fingerprint residues"; Science and Justice; Vol 58, issue 2,2018