Molecular composition of fingermarks: Assessment of the intra- and inter-variability in a small group of donors using MALDI-MSI

Revealing the Elemental Distribution within Latent Fingermarks Using Synchrotron Sourced X-ray Fluorescence Microscopy

“…Ourselves and others have previously demonstrated the high level of interdonor variability that exists with respect to organic composition and distribution within fingermarks. ,,, Despite the well characterized heterogeneity in organic composition of fingermarks, the variability in inorganic composition has been less studied due to the previous unavailability of suitable techniques . The capability of XFM for rapid, micron level spatial resolution elemental mapping now provides for the first time the opportunity to assess interdonor variability in elemental composition and distribution within natural fingermarks.…”

Interpol review of fingermarks and other body impressions 2016–2019

“…Given that they refer to unconventional approaches or are based on limited sets of fingermarks, caution should be taken with regards to some expressed conclusions. Donor profiling – The following studies aim at providing additional information from a fingermark, other than the ridge pattern: a new biometric identification tool built on an amino acid-based chemical assay [ 184 ]; donor-related information (i.e., gender, ethnicity, and donor age) obtained from secretion residue lipid profiling (technique: DESI-MSI) [ 185 ]; impact of gender and ethnicity on the lipid composition of residues present on an individual’s fingertips (technique: HPLC-ACPI-MS) [ 186 ]; donor gender determination using an amino acid-based chemical assay [ 187 ] or by specifically targeting the chromosomes X and Y contained in nucleated cells (technique: fluorescent in situ hybridization) [ 188 ]; donor characteristics and behavioural information (e.g., gender, ethnicity, diet, occupational activities, use of hand sanitizers) gained from bacterial profiling [ 189 ]; impact of donors and secretion types (i.e., eccrine, sebum-rich, and natural) on secretion residue composition (technique: MALDI-MSI-based metabolomics approach combined with chemometrics tools) [ 190 ]. Evolution of secretion residue with time – Surface adhesion monitoring and topography variation (technique: PeakForce QNM AFM) [ 191 ]; molecular composition variation (e.g., carotenoids, squalene, unsaturated fatty acids and proteins – technique: Raman spectroscopy) [ 192 ]; migration imaging of endogenous fatty acids contained in sebum-rich fingermarks (technique: hyperspectral SRS) [ 193 ]; topological modifications (e.g., decrease of ridge height from 200 nm to 100 nm over three days – technique: AFM) [ 194 ]; thermal degradation of sebum-rich fingermarks (technique: FTIR microspectroscopy) [ 195 ]; intermolecular interactions between lipids (technique: FTIR microspectroscopy) [ 196 ], physical modifications of fingermarks left on metallic substrates (technique: EIS) [ 197 ], secretion residue composition variation (technique: SALDI-MS combined with MCF) [ 198 ] – caution: the last approach requires the dusting of nano-sized MCF (See section 3.2.6 for details).…”

“…Donor profiling – The following studies aim at providing additional information from a fingermark, other than the ridge pattern: a new biometric identification tool built on an amino acid-based chemical assay [ 184 ]; donor-related information (i.e., gender, ethnicity, and donor age) obtained from secretion residue lipid profiling (technique: DESI-MSI) [ 185 ]; impact of gender and ethnicity on the lipid composition of residues present on an individual’s fingertips (technique: HPLC-ACPI-MS) [ 186 ]; donor gender determination using an amino acid-based chemical assay [ 187 ] or by specifically targeting the chromosomes X and Y contained in nucleated cells (technique: fluorescent in situ hybridization) [ 188 ]; donor characteristics and behavioural information (e.g., gender, ethnicity, diet, occupational activities, use of hand sanitizers) gained from bacterial profiling [ 189 ]; impact of donors and secretion types (i.e., eccrine, sebum-rich, and natural) on secretion residue composition (technique: MALDI-MSI-based metabolomics approach combined with chemometrics tools) [ 190 ].…”

Revealing Contamination and Sequence of Overlapping Fingerprints by Unsupervised Treatment of a Hyperspectral Secondary Ion Mass Spectrometry Dataset

“…Visible fingerprints are formed when the skin has traces of colored substances such as blood, ink, pollutants, or other chemicals, and invisible, when no such substances are found, and specific treatments are required to reveal them. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) chemical imaging is a field of increasing interest owing to the enormous quantity of forensic information it can generate. − ToF-SIMS has been successfully applied to chemical imaging of banknotes for (a) revealing invisible fingerprints, (b) identifying illicit drugs on fingerprints, (c) age-dating of fingerprints based on the diffusion of organic molecules, and (d) chronicling fingerprint deposition on documents. , …”