1 An Examination of the Sequence of Intersecting Lines using Attenuated Total Reflectance – Fourier Transform Infrared Spectral Imaging* 1 1 1 Katherine Bojko, B.Sc.(Hons); Claude Roux, Ph.D.; and Brian J. Reedy, Ph.D. 1 Centre for Forensic Science, University of Technology, Sydney, PO Box 123, Broadway NSW 2007 Australia. Author to whom correspondence should be addressed: Brian J. Reedy, Ph.D. Department of Chemistry, Materials and Forensic Science University of Technology, Sydney PO Box 123 Broadway NSW 2007 Australia Telephone: +61 2 95141709 Fax: +61 2 95141460 E-mail:
[email protected] *This work was presented, in part, by Katherine Bojko (nee Flynn) et al. at the 57th Annual Meeting of the American Academy of Forensic Sciences, New Orleans, LA, USA, February 2005; and the 17th Meeting of the International Association of Forensic Sciences, Hong Kong, China, August 2005. Short running header BOJKO ET AL. • SEQUENCE OF INTERSECTING LINES Color versions of the figures can be found online at www.blackwellsynergy.com 2 ABSTRACT: In this study, the potential of attenuated total reflectance – Fourier transform infrared (ATR-FTIR) spectral imaging as a technique to determine the sequence of line crossings was examined. The technique was successful in determining the sequence of heterogeneous line intersections produced using ballpoint pens and laser printers. By imaging at characteristic frequencies, it was possible to form spectral images showing the spatial distribution of the materials. By examining the spectral images from the inks, it was possible to determine whether the ink was above or below the toner. In blind testing, ATR-FTIR spectral imaging results were directly compared to those obtained by eight experienced forensic document examiners using methods regularly employed in casework.