Infrared Spectroscopic Imaging for Noninvasive Detection of Latent Fingerprints

Abstract

The capability of Fourier transform infrared (FTIR) spectroscopic imaging to provide detailed images of unprocessed latent fingerprints while also preserving important trace evidence is demonstrated. Unprocessed fingerprints were developed on various porous and nonporous substrates. Data-processing methods used to extract the latent fingerprint ridge pattern from the background material included basic infrared spectroscopic band intensities, addition and subtraction of band intensity measurements, principal components analysis (PCA) and calculation of second derivative band intensities, as well as combinations of these various techniques. Additionally, trace evidence within the fingerprints was recovered and identified.

Effect of substrate surface topography on forensic development of latent fingerprints with iron oxide powder suspension

“…Advances in nanotechnological techniques enable the use of new methodologies for making and augmenting crime scene identifications [13][14][15]. Research into nanostructured particles [4, 16,17] has helped develop techniques with improved latent fingerprint development, though efficacy remains surface dependent [4,17].…”

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

“…Crane et al demonstrated the ability of IR HSI to detect latent untreated fingermarks on various porous backgrounds (copier paper, cigarette butt paper, U.S. dollar bill, postcard) and nonporous backgrounds (trash bags, a soda can, tape) [27]. Fingermarks on the soda can and a black trash bag were clearly visible when viewing the intensity band image at 9842 nm (asymmetric O-C-C stretch ester) (see Figure 7).…”

“…Eccrine deposits mainly consist of amino acids, inorganic compounds, and proteins, while sebaceous material consists primarily of fatty acid esters [25]. The chemistry of these residues varies among individuals and it shows increasing amounts of sebaceous deposits with age [26,27]. Fingermark detection techniques aim to create contrast between the ridge details of a latent fingermark and the background on which it is located.…”

“…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.…”