Wednesday 9th July

12 – 1 pm

Rm 312.222

Simon Lewis

Department of Chemistry, Curtin University

Contacts Leaving Traces: Synchrotron source infrared spectroscopy of forensic exchange evidence

Abstract

Locard’s Exchange Principle is a key tenet of forensic science, and is relied upon by forensic investigators in order to establish links between persons, objects and locales. This presentation provides an overview of our recent studies utilising the Infrared beamline at the Australian Synchrotron to study various forms of exchange evidence. Synchrotron infrared (IR) microscopy is ideally suited for this research due to its high spatial resolution and improved sensitivity compared to conventional IR microscopy. We have used high spatial resolution synchrotron source transmission IR spectra of paint thin sections to examine the migration of components between the various paint layers [1] and to study primer surfacer coats from a large population of vehicles of known origin [2].  Using chemometrics the primer surfacer data was classified into 14 groups that related to the country of manufacture, manufacturer and manufacturing plant, and in some cases an indication of the year of manufacture [2]. The successful development of latent fingermarks relies heavily upon the chemistry of the latent fingermark residue itself. We have used synchrotron IR microscopy to study the chemical composition of latent fingermarks, with particular regard to the ageing of the fingermark [3].

[1]     Maric, M., van Bronswijk, W., Lewis, S. W., & Pitts, K. (2014). Synchrotron FTIR characterisation of automotive primer surfacer paint coatings for forensic purposes. Talanta, 118(0), 156-161.
[2]     Maric, M., van Bronswijk, W., Lewis, S. W., Pitts, K., & Martin, D. E. (2013). Characterisation of chemical component migration in automotive paint by synchrotron infrared imaging. Forensic Science International, 228(1–3), 165-169.
[3]     Fritz, P., van Bronswjik, W., Lepkova, K., Lewis, S. W., Lim, K. F., Martin, D. E., & Puskar, L. (2013). Infrared microscopy studies of the chemical composition of latent fingermark residues. Microchemical Journal, 111(0), 40-46.

Biographical Details

Simon Lewis is Professor of Forensic and Analytical Chemistry and Director of Teaching and Learning in the Department of Chemistry at Curtin University, Perth, Western Australia. He obtained a his PhD in Analytical Chemistry from the University of Plymouth, UK before taking up a position as a lecturer at Deakin University, Geelong, Australia (1994-2005) where he was involved in developing and coordinating the undergraduate forensic science program .  His research is focused on chemical techniques applied to forensic analysis and has been carried out in collaboration with various forensic science providers including ChemCentre, Western Australia Police, AFP, Forensic Science South Australia, Victoria Police Forensic Services Department and the US Secret Service. He has published in excess of 80 peer reviewed papers and book chapters in the areas of analytical and forensic chemistry. His research on fingerprint detection has resulted in invitations to present at meetings of the International Fingerprint Research Group (IFRG), in Canberra, Australia (2007), Lausanne, Switzerland (2009), Linkoping, Sweden (2011) and most recently in Israel (2013). Attendance at an IFRG meeting is by invitation only and represents recognition of relevant research contributions in the field.  He is on the editorial advisory boards of the Journal of Forensic Identification and the recently published Elsevier Encyclopedia of Forensic Sciences (2nd Edition) (with specific responsibility for Analytical Techniques). Prof Lewis currently serves on the Program Advisory Committee for the Infrared Beamline at the Australian Synchrotron. In addition to his research and teaching he is enthusiastically involved in out-reach programs, using forensic science and analytical chemistry as vehicles to engage children of all ages in science. His activities in forensic science and chemistry education have been recognised by a number of awards at the university and national level including in 2009 an Australian Learning & Teaching Council (ALTC) Award for Teaching Excellence in the category of Physical Sciences and Related Studies.