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Smartphone Technology for Capturing Untreated Latent Fingerprints Feasibility Research

NCJ Number
Date Published
July 2013
98 pages
This research determined the feasibility of using digital images of untreated latent fingerprints for identification using a Canon SLR and a Smartphone camera in order to support the original proposal of creating a portable handheld imaging device for latent fingerprints.

Although not all the images taken from all the substrates produced detailed fingerprint ridges, researchers were able to capture latent prints from smooth, flat, non-porous substrates with third-level detail, the highest level achievable. Other images from textured, flat, non-porous substrates produced latent fingerprints with second-level detail. The study concludes that although digital imaging of untreated latent fingerprints has limitations, it can be used as a viable substitute to dusting when dusting is not a necessity and the ridge details can be captured and examined using the techniques and procedures followed in this research. Although the Canon 7D camera had various settings to control the light exposure, the smartphone used in the experiment was unable to compensate for the different lighting levels. Two disadvantages for the smart phone were lack of camera configuration settings and a small sensor size that results in poor light exposure and increased pixel noise. Researchers determined that the incident light angle and proper light exposure were the most important aspects of photographing latent fingerprints. The light source provided the best exposure when it was placed "in line" with the viewing angle. Further research into smartphone technology could be useful in determining the best available options for improving the image quality of untreated latent fingerprints. Larger camera sensors, improved camera settings, and improved lighting options would result in the same image quality as those captured with the Canon 7D camera. This would result in a further improvement in the portability and compactness of the imaging system. A detailed description of materials and methods, references, and appended images collected and camera specifications

Date Published: July 1, 2013