The Detection and Enhancement of Latent Fingermarks Using Infrared Chemical Imaging

Abstract

The use of a new technique, Fourier transform infrared (FTIR) chemical imaging, has been demonstrated for the enhancement of latent fingermarks on a number of surfaces. Images of untreated fingermarks on glass backgrounds with excellent ridge detail were acquired using infrared chemical imaging. High quality fingermarks on glass backgrounds were also developed using ethyl cyanoacrylate (super glue) fuming and subsequent infrared chemical imaging. This new method allows the collection of images from backgrounds that traditionally pose problems for current fingermark detection methods. The background may, for example, be highly colored, have a complex pattern, or possess other pattern or image characteristics that make it difficult to separate fingermark ridges using traditional optical or luminescent visualization. One background that has proven to be a challenging surface for the development of latent fingermarks is the Australian polymer banknote. To demonstrate the power and applicability of infrared chemical imaging, fingermarks fumed with ethyl cyanoacrylate were successfully imaged from Australian polymer banknotes.

Visualisation of latent fingermarks on polymer banknotes using copper vacuum metal deposition: A preliminary study

“…The use of upconversion powders, such as that by Ma et al, has been suggested as an alternative method to help overcome problematic backgrounds [9]. Tahtouh et al also utilised IR imaging in the form of Fourier transform infrared (FTIR) to enhance fingermarks on a number of substrates, including polymer banknotes, which contained untreated and cyanoacrylate treated fingermarks [10]. Such a process, however, requires expert operator input and can be largely time consuming.…”

Spectroscopic Imaging of Latent Fingermarks Collected with the Aid of a Gelatin Tape

“…[2][3][4][5][6][7][8] The application of ATR-FT-IR imaging for the study of the chemical composition of various residues contained in adult fingerprints was demonstrated by Ricci et al 9 At crime scenes, marks developed on textured or patterned backgrounds may be difficult to visualize in situ, and therefore, it may be desirable to collect fingermarks from crime scenes so that they can be transported for further examination in a laboratory or in a fingerprint bureau. Traditionally, many fingermarks are developed at crime scenes by powdering (e.g., with aluminum flake powder) and are recovered for subsequent evaluation by lifting them from the surface on clear adhesive tape.…”

Hyperspectral imaging for non-contact analysis of forensic traces

“…different materials, porous, non-porous, colored, patterned, etc.) which may complicate the measurements [27][28][29][30][31]35]. Comparison of spectra on different backgrounds typically requires advanced system calibration and data analysis.…”