DOI: 10.5281/zenodo.17122875
title: Fingermark composition - m/z intensities (MALDI-MSI)

description: Table embedding the intensities associated to the m/z (source: MALDI-MSI) detected in 308 fingermarks, collected from 13 donors over a one-year time-frame.

This file will contain the data used for the intervariability study:- sample name- donor number- intensities associated to each m/z for each sample (note: for ethical reasons, each m/z value has been replaced by an alpha-numerical code X##).

The reuse of the data must be acknowledged in publications and public presentations related with the study (e.g., meetings). 
description: During the last decade, an increasing number of studies focused on the analysis of fingermark composition to offer evidential proof of a criminal activity (e.g., drug consumption, explosive manipulation, sexual assault) or to provide intelligence about the individual who has left the fingermark (e.g., gender, diet, lifestyle). If these claims seem appealing from a scientific point of view, some conclusions are over-rated with regards to forensic science or to actual investigative benefits. This discrepancy is mostly due to limited experimental settings and to limitations imposed by the investigative frame or by the nature of the traces related to casework. This project aims at strengthening the knowledge gained from the composition of fingermarks and at assessing how emerging practices may offer additional value to the forensic community. To reach that objective, we have explored an original route: considering the secretion residue as a whole to extract a molecular signature from it, instead of trying to identify compounds linked to specific activities. If fingermarks from a given individual are characterized by a molecular signature that can be distinguished from others, it would constitute a relevant way of considering the chemical composition of fingermarks in an investigative framework.

The overall objective of this project is to investigate further the fingermark composition as a third discriminative element obtained from fingermarks, in addition to the ridge pattern or the genetic material it may contain (i.e., touch-DNA). To reach that goal, we propose to:[Aim-1] Collect and pre-process data from an extended set of fingermarks, using MALDI-MSI[Aim-2] Investigate the long-term stability of the molecular signature for a given individual (intravariability)[Aim-3] Investigate the difference in molecular signatures between individuals (intervariability)[Aim-4] Initiate the introduction of the molecular signature into a forensic argumentation

The consideration of an extended set of donors and a timeframe with variable granularity, as well as the development of in-house computational tools allowing an automated processing of the complex datasets generated by this approach, will bring new insights into the exploration of these scopes. It is expected that the outcomes of this study will benefit the forensic community in two ways: research and investigation. Indeed, from the feasibility study, it appeared that the molecular signature can be associated witha tuneable level of specificity. From the differentiation of the secretion types for a given individual (useful for research) to the differentiation of individuals (useful for investigation), the outcomes of this study would bring additional fundamental knowledge to the field.