Initial Results on the Composition of Fingerprints and its Evolution as a Function
of Time by GC/MS Analysis

Abstract

: Determining the time since deposition of fingermarks may prove necessary to assess their relevance to criminal investigations. The crucial factor is the initial composition of fingermarks, because it represents the starting point of any aging model. This study mainly aimed to characterize the initial composition of fingerprints, which show a high variability between donors (inter‐variability), but also to investigate the variations among fingerprints from the same donor (intra‐variability). Solutions to reduce this initial variability using squalene and cholesterol as target compounds are proposed and should be further investigated. The influence of substrates was also evaluated, and the initial composition was observed to be larger on porous surface than nonporous surfaces. Preliminary aging of fingerprints over 30 days was finally studied on a porous and a nonporous substrate to evaluate the potential for dating of fingermarks. Squalene was observed to decrease in a faster rate on a nonporous substrate.

Chemical Characterization of Latent Fingerprints by Matrix-Assisted Laser Desorption Ionization, Time-of-Flight Secondary Ion Mass Spectrometry, Mega Electron Volt Secondary Mass Spectrometry, Gas Chromatography/Mass Spectrometry, X-ray Photoelectron Spectroscopy, and Attenuated Total Reflection Fourier Transform Infrared Spectroscopic Imaging: An Intercomparison

“…Squalene was found to be present at much lower levels relative to other fatty acids than previously reported values of 7−11 μg per fingerprint. 3,11 This may be a consequence of the sampling protocol used in each of the studies. The full range of detected compounds is tabulated in Table 1.…”

Development of Laser Desorption Imaging Mass Spectrometry Methods to Investigate the Molecular Composition of Latent Fingermarks

“…Much of the prior research for the detection and identification of endogenous substances in fingermarks has been carried out using gas chromatography-mass spectrometry (GC-MS). Despite the fact that this technique is destructive and limited to a small class of compounds (<500 Da), it allows the detection of endogenous substances, such as amino acids, fatty acids, wax esters, squalene, and cholesterol, as well as the detection of some exogenous substances coming from hair product, parfum residue, cosmetics, and skin lotion [11][12][13][14][15][16]. Many nondestructive MS techniques have been developped for the detection of endogenous and exogenous substances from fingermarks.…”

Métodos para Análise do Tempo desde a Deposição de Manchas de Sangue em Cenas de Crime: Um Diagnóstico Comparativo

“…Uma prova criminal pode perder a sua relevância jurídica, caso não seja demonstrado que o seu tempo de produção está relacionado com o momento em que um crime foi cometido 3 , e essa indagação está entre as mais desafiadoras no campo das ciências forenses 4 . O processamento de uma cena de crime é considerado como um dos aspectos mais críticos de investigações criminais eficazes.…”