The present invention is directed to a method for determining the presence of a residue on or within a fingerprint using matrix-assisted mass spectrometric techniques. The matrix-assisted mass spectrometric technique can be selected from Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Time-Of-Flight Mass Spectrometry (MALDI-TOF-MS) and/or Surface Assisted Laser Desorption/Ionisation Time-Of-Flight Mass Spectrometry (SALDI-TOF-MS).
