NCJ Number
184285
Journal
Journal of Forensic Identification Volume: 50 Issue: 4 Dated: July-August 2000 Pages: 344-350
Date Published
2000
Length
7 pages
Annotation
This article reports on an experiment designed to answer questions pertinent to whether a fingerprint found in blood was from a bloody finger or from a fingerprint already on the surface that was developed by the blood.
Abstract
In the experiment, a single blood drop was deposited onto a dry surface and then touched, and a single drop of blood was placed on a finger and applied to the same surface. Also, fingerprints were deposited on a painted metal sheet by using a finger wet with blood in varied amounts. The experiments found that blood will not visualize previously deposited eccrine prints, since there is not enough organic material present to influence the manner in which the blood wets or adheres to the surface. Blood smeared across a greasy fingerprint can visualize the print; however, the ridge structure and furrows will be reversed. In some areas the blood will pool, causing a speckling, so visualization is not consistent throughout. A difference was found in a grease print on a horizontal surface and a vertical surface. As the plane of the surface is moved from horizontal, less blood stays in the furrows. The experiments also concluded that it cannot always be determined whether a single drop of blood was on the surface or on the finger; however, a print left by a bloody finger can be distinguished from a light blood smear over a grease print; and a fingerprint deposited by a finger with blood on it can be distinguished from a fingerprint left in grease or oil and revealed by brushing it with blood. 5 figures and 2 references