| Popis: |
Time since deposition is a type of intelligence enabling to address activity level propositions. In relation to a fingermark, this information would provide an additional evidential value by proving/disproving the presence of a suspect at the time of the crime. Whilst fundamentally important, this type of intelligence remains, to date, elusive to the forensic community. This is due to the significant number and interplay of factors that can affect the determination of age. Mass spectrometry (MS) has greatly contributed to the understanding of the changes occurring within the molecular composition of a fingermark over time, especially with regard to lipids. In particular, the hyphenation of chromatography with mass spectrometry has enabled to analyse and monitor over time the complexity of the molecular lipid composition for both volatile and non-volatile species. However, these approaches require extraction of the fingermark molecular components, and as such they are completely destructive. Conversely, chemical imaging methods allow to keep the fingermark intact by enabling in situ analysis. In addition, due to the very nature of mass spectrometry imaging, these methods offer contextual intelligence, that is, time since deposition (potentially) and biometric information for suspect identification; this is particularly desirable when conventional fingermark enhancement methods yield partial, scarce or no ridge detail. |
