Abstract
Fingermarks are trace evidence of great forensic importance, and their omnipresence makes them pivotal in crime investigation. Police and law enforcement authorities have exploited fingermarks primarily for personal identification, but crucial knowledge on when fingermarks were deposited is often lacking, thereby hindering crime reconstruction. Biomolecular constituents of fingermark residue, such as amino acids, lipids and proteins, may provide excellent means for fingermark age determination, however robust methodologies or detailed knowledge on molecular mechanisms in time are currently not available. Here, we address fingermark age assessment by: (i) drafting a first protein map of fingermark residue, (ii) differential studies of fresh and aged fingermarks and (iii), to mimic real-world scenarios, estimating the effects of donor contact with bodily fluids on the identification of potential age biomarkers. Using a high-resolution mass spectrometry-based proteomics approach, we drafted a characteristic fingermark proteome, of which five proteins were identified as promising candidates for fingermark age estimation. This study additionally demonstrates successful identification of both endogenous and contaminant proteins from donors that have been in contact with various bodily fluids. In summary, we introduce state-of-the-art proteomics as a sensitive tool to monitor fingermark aging on the protein level with sufficient selectivity to differentiate potential age markers from body fluid contaminants.
Highlights
Fingermarks are trace evidence of great forensic importance, and their omnipresence makes them pivotal in crime investigation
The recorded proteomic profile is in line with that observed from the skin surface[18,19], with cytokeratins as dominant protein species
Similar grouping is displayed by the functional and biological process annotation; structural proteins involved in skin development and keratinocyte differentiation, which prevail in fingermark residue, and homeostatic proteins that form a smaller subset
Summary
Fingermarks are trace evidence of great forensic importance, and their omnipresence makes them pivotal in crime investigation. Upon deposition on a substrate, the protein composition of fingermarks is likely to change, whereas rates of degradation as well as alterations originating from e.g. oxidation, deamidation or alkylation processes will vary, depending notably on environmental conditions and time This makes these biomolecules good targets to assess crucial yet presently unavailable temporal information for crime investigation. A bottom-up proteomics approach (Fig. 1a) was applied to confidently identify protein traces and assess the fingermark proteome dynamic changes at different stages of ageing (hereafter referred to as ‘ageing study’) This approach was applied to contaminated fingermarks to examine fingermark ageing in light of realistic forensic scenarios and detect donor contact with bodily fluids (hereafter referred to as ‘donor contact study’). Unrestrictive searches of these proteomics data were performed to assess protein damage and modification during ageing
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
