Detection of exogenous substances in latent fingermarks by silver-assisted LDI imaging MS: perspectives in forensic sciences

Abstract

For over one hundred years, the fingerprint has reigned as one of the most trusted pieces of forensic evidence for suspect identification. In the last few decades, the modernization of chemical analysis technologies led scientists to explore new possibilities to further analyse fingermarks sampled from a crime scene. Indeed, the detection of chemicals a suspect has been in contact with before or during the crime can provide valuable insights into criminal investigations. In this regard, imaging mass spectrometry (IMS) has shown to be a powerful tool for the analysis of fingermarks by combining suspect identification and the detection of numerous endogenous and exogenous compounds. A novel approach developed in our laboratory, silver-assisted laser desorption ionization (AgLDI), was adopted to allow for the chemical analysis of latent fingermarks left on nonconductive surfaces (such as paper, cardboard, plastic and forensic lifting tape) with a time-of-flight mass spectrometer. In this study, we continue to evaluate the potential of AgLDI IMS to provide circumstantial evidence by detecting exogenous substances. We first demonstrate that owner-specific chemical signatures can be recovered from fingermarks based on the presence of several cosmetics and personal care products. We then show the possibility of detecting and imaging fingermarks containing three common illicit drugs, namely tetrahydrocannabinol, cocaine and heroin. Finally, we demonstrate that the methodology also allows us to successfully image bloody fingermarks after appropriate forensic enhancement treatments. Overall, we believe that AgLDI IMS has significant potential that could positively contribute to forensic investigations.

The forensic exploitation of fingermark chemistry: A review

“…Procaine Kaplan-Sandquist, LeBeau, and Miller (2014), Kaplan-Sandquist, LeBeau, and Miller (2015) Quetiapine (antipsychotic drug) Costa, Frampas, et al (2019), Sympathomimetics: methylephedrine [ephedrine], pseudoephedrine Kaplan-Sandquist et al (2014), Kuwayama et al (2014), Kaplan-Sandquist et al (2015), Fowble and Musah (2019) Terbinafine (antifungal drug) Lim and Seviour (2012) 9-Tetrahydrocannabinol (THC) [11-nor-9-carboxy-Δ 9tetrahydrocannabinol, tetrahydrocannabinolic acid] Hazarika et al (2008), Ifa, Manicke, Dill, and Cooks (2008), Groeneveld et al (2015), Lauzon and Chaurand (2018), Hudson et al (2019) Verapamil Yagnik, Korte, and Lee (2013) The examples given above are only some of the materials that may be found and providing an exhaustive list is not possible here. Blood is probably the most significant contaminant that may be encountered in a fingermark at a crime scene.…”

Criminal profiling through MALDI MS based technologies – breaking barriers towards border-free forensic science

“…However, fingerprinting has remained at large unchanged and unchallenged in terms of workflow, scope and visualisation techniques. But despite successful, there is a number of scenarios, in which the process of matching a crime scene mark to a fingerprint record fails, for example because the mark is smudged, partial, empty, overlapped or beyond the Always employed for direct biometric identification exploiting the ridge pattern characteristics, the chemical composition of a mark can indeed additionally reveal personal information about its owner which can be used to support an investigation; it may be particularly useful when the ridge detail is insufficient or the mark composition can be linked to a better physical quality mark of the same owner at the crime scene, thus helping with the crime scene dynamics reconstruction 3 . Through detecting substances that are normally produced by our body and present in sweat, and therefore in fingermarks, so called endogenous, those that have entered the body and have been excreted through sweat (semiendogenous), for example through medications, drugs etc., and those that come in contact with our fingertips (exogenous) we can potentially undertake a sort of criminal profiling 4 .…”

Potential of triacylglycerol profiles in latent fingerprints to reveal individual diet, exercise, or health information for forensic evidence

“…7 Research has also shown that exogenous compounds in ngerprints can be used to connect an individual to a certain lifestyle or illicit activity. [8][9][10][11] Mass spectrometry imaging (MSI) provides the advantage of simultaneous collection of both chemical and spatial information, making it popular for the analysis of latent ngerprints because an image that could be used for a database search is generated while additional chemical information is being obtained. As a surface technique, MSI requires very little sample preparation.…”