MALDI-MSI Imaging of Latent Fingerprints

For years, forensic scientists have been seeking new methods to improve existing techniques for the visualization of latent fingerprints. The structured combination of optical methods (diffused reflection, luminescence, UV absorption and reflection), physical methods (powdering, vacuum metal deposition, small particle reagent), physico-chemical methods (physical developer, multi-metal-deposition, iodine, cyanoacrylate), and chemical methods (ninhydrin and its analogues, DFO, etc.), permits a highly efficient processing of the secretions deposited by the fingers on a great variety of substrates. To visualize these developed fingerprints, alternative light sources or laser-based detection methods are commonly used. However, like all other existing techniques, these optical methods do not work in all possible cases, and certain types of latent fingerprints or object surfaces with unique characteristics may be problematic.