NCJ Number
113378
Journal
Journal of Forensic Identification Volume: 38 Issue: 5 Dated: (September-October 1988) Pages: 227-230
Date Published
1988
Length
4 pages
Annotation
This article summarizes aspects of 'reverse color' fingerprint images, which have gray or white ridges compared to the standard black ridge prints.
Abstract
Reverse color prints have become more common due to the increase in latent prints being developed, especially by the cyanoacrylate method. The color of the ridge detail of a latent print is dependent upon several factors: the background color, the method or reagent used to visualize the print, and whether the ridges or the valleys/furrows are developed. The ability to determine whether an impression is a reverse color print is of utmost importance, since ridge details must be compared with ridge details to effect an identification. Unless aware that a print is in reverse color, an examiner will unknowingly compare the valleys on the latent with the ridges on a fingerprint, palmprint, or footprint card. Latent print examiners should be familiar with the photographic techniques used to reverse the color of ridge detail. Comparisons are made by using latent print photographs of natural size with the ridges appearing dark on a light background. One aspect sometimes overlooked by fingerprint experts is that a latent print may be in reverse color even though black powder, ninhydrin, or some other process is used to develop the print. Some of the reasons for this are removal of surface material by touching, clean and dry ridge summits while valleys are not, and excess pressure. 1 figure, 3 references.