Analysis of the composition of latent fingermarks by spectroscopic imaging techniques.

Despite the success of DNA fingerprinting, fingermarks remain an efficient means of ascertaining the identity of an individual at many crime scenes. There are numerous enhancement techniques used to develop fingermarks on a range of deposition surfaces. Despite this, there is a need for further intelligence to be gained in situations where fingermarks retrieved at crime scenes do not yield identification.The majority of the work presented in this thesis utilises MALDI mass spectrometry in profiling and imaging mode to investigate latent fingermarks, with SERS and ATR-FTIR used as complementary techniques.One of the major issues of using analytical techniques to investigate latent fingermarks is their inadequate application to real crime scene scenarios. Presented within this thesis is a new method of matrix application that makes MALDI-MSI forensically applicable and enables the distribution of various endogenous lipids and exogenous compounds within fingermarks to be visualised.The work is extended to include detection of various antimicrobial peptides and small proteins in the fingermarks of a cohort of 80 donors using MALDI mass spectrometry profiling followed by multivariate statistical analysis in an attempt to differentiate donors based on their sex.Chemical imaging of latent fingermarks by SERS and ATR-FTIR is also demonstrated, which could potentially lead to a three step multi-informative analytical approach for chemical characterisation of fingermark residue.