NCJ Number
197826
Journal
Journal of Forensic Identification Volume: 52 Issue: 6 Dated: November/December 2002 Pages: 750-761
Editor(s)
Alan L. McRoberts
Date Published
November 2002
Length
12 pages
Annotation
This article presents four scenarios exploring the effectiveness of digital evidence enhancement techniques and recommends specific procedures for the maximum recovery of evidence when analog techniques fall short.
Abstract
Images of crucial evidence may be very fragile, as well as difficult to see creating a wide range of photographic challenges at crime scenes for evidence photographers. Under most circumstances, conventional photographic procedures work successfully to record evidence. This article sets out to recommend specific procedures for the maximum recovery of evidence when conventional techniques are no longer acceptable, specifically digital evidence enhancement techniques. Four scenarios are presented to explore the effectiveness of digital techniques. Images were captured on a Nikon D-1 digital camera as 24 bit RGB images in a TIF format and were 7.56 MB in size. The first scenario included a dust shoeprint that was deposited on the cloth surface of a chair. In the second scenario, fingerprints were placed on patterned wallpaper and treated with ninhydrin, recreating an actual homicide scene. Scenario three consisted of a fingerprint deposited in grime on patterned wallpaper to emulate visible dirt impressions. In the final scenario, a fingerprint was developed on patterned wallpaper with ninhydrin, similar to scenario two. Seven conclusions were drawn: (1) each of the scenarios noted that the potential exists for extracting more information with the use of a computer technique than with just photography; (2) computer techniques are not merely an extension of photography, but an integral part of the initial capture; (3) conventional photographs should be included in this documentation; (4) the implications do not imply employing digital imaging exclusively; (5) the potential for significant saving in time by application of digital recording and enhancement techniques; (6) more clarity and contrast in a latent print aids a fingerprint examiner in determining if an identification can be effected: and (7) a single finger impression may consist of isolated areas of ridge detail that are distinct and continuous, but lack sufficient detail independently to base a conclusion of either elimination or identity. Figures