NCJ Number
79979
Journal
Police Magazine Volume: 4 Issue: 6 Dated: (November 1981) Pages: 42-47
Date Published
1981
Length
6 pages
Annotation
The methods and evidence strength of fiber analysis are discussed, with particular attention to the pending Wayne Williams Atlanta case.
Abstract
The postwar boom in synthetic fibers has produced a wide variety of fabrics, often having minute differences. In recent decades, forensic scientists have developed sophisticated techniques for comparing fiber characteristics to determine whether they are similar. Synthetic fibers are essentially identified by their chemical differences, along with shape and cross-section. Because use of synthetic fibers is so widespread, however, investigators have not been able to say conclusively that a fiber found on a victim or at a crime location could only have come from an item associated with a suspect. For this reason, many legal professionals view fiber analysis evidence as inadequate grounds for conviction by itself. In the Wayne Williams case, fibers from the two victims and the suspect have been subjected to both standard and advanced research techniques. In addition to microscopic analysis, a test called birefringence has also been used. This is a technique designed to measure the comparative composition of substances by passing polarized beams of light through them and measuring how the light is refracted. Other fiber analysis techniques used in the case were microspectrophotometry, which uses ultraviolet light and sophisticated machinery to obtain a highly exact measurement of a fiber color, and neutron activation, a process that determines the quantity of different chemical elements in fibers. There are new fiber analysis techniques still in the experimental stages. Randall Bresee of Kansas State University is developing three techniques intended to measure the different environments and influences to which a fiber has been subjected. Other new forensic fiber analysis techniques being developed in other countries are briefly described. No references or footnotes are provided.