Preliminary analysis of latent fingerprints recovered from underneath bloodstains using matrix-assisted laser desorption/ionization fourier-transform ion cyclotron resonance mass spectrometry imaging (MALDI FT-ICR MSI)

Abstract Fingerprints and bloodstained evidence contain information critical to a forensic investigation as they both offer the potential for individual identification through comparison of friction ridge details or DNA profiling, respectively. Despite the strong evidentiary value of both types of exhibits, no method currently exists for the collection of fingerprints deposited underneath bloodstains without destruction of the fingerprint. This study evaluates a novel fingerprint recovery method using high-resolution mass spectrometry profiling and imaging. Latent fingerprints were recovered from underneath bloodstains by gently washing the bloodied surfaces with a dilute solution of anti-coagulant, and Matrix-Assisted Laser Desorption/Ionization Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (MALDI FT-ICR MS) was then used to compare the compositional variation of latent and chemically washed fingerprints. In profiling mode, 55% of residues detected in latent fingerprints were preserved after chemical washing, with greater detection frequency of sebaceous secretions. Conversely, mass spectrometry imaging analysis showed better representation of eccrine residues, where compounds such as phenol were found to increase in intensity by approximately 20% after chemical washing. Traditional fingerprint development powders were also used on recovered fingerprints to demonstrate the compatibility of the method with current forensic practice. The results of this study indicate the success of the fingerprint recovery method, highlighting its potential for use in future forensic casework to increase the evidentiary value of seized bloodied objects.