Question #3: In what respects did the use of fiber evidence in the Wayne Williams trial differ significantly from its use in previous cases?

Numerous criminal trials over the years have used fiber evidence. In 1936, the wife of a NBC executive was murdered and the killer caught partly due to fibers from twine used to bind her during the murder. Ted Bundy was convicted of the murder of a 12-year old girl partly due to fibers found in his van. The trial of Wayne Williams, also based on fiber evidence, differed from other cases in several significant ways.
From July 1979 to May 1981, thirty black children and young men were reported missing or found dead in the area of Atlanta, Georgia. The Georgia State Crime Lab found yellow-green nylon fibers and violet acetate fibers on the bodies and clothing of victims. The fibers from the different victims were generally similar to each other, linking them to a single source and tying them to one killer. The Wayne Williams case was the first time fiber evidence played a significant role in a case involving a large number of murder victims.
An Atlanta newspaper wrote an article about several different fibers being located on the bodies. After the article, bodies located in the Atlanta area rivers were nude or clothed only in underwear. The release of the information caused a change in the way the suspect disposed of bodies, in an apparent effort to eliminate fiber evidence. Media attention appeared to result in a change in pattern of the suspect. Media attention on the murders and the Williams trial was unique due to the amount and detail of the coverage. After Williams was discovered on a Chattahoochee River bridge, police ultimately discovered carpet in Williams’ home with fibers matching those on the victims. The fibers were ultimately determined to have been produced by the Wellman Corporation and West Point Pepperell made them into carpeting, the same as in Williams’ home. West Point Pepperell only made the carpet, using Wellman fiber, for one year and the unusual color was very limited. During the trial, experts showed that all of the fibers present on the bodies had a very high probability of coming from association with Williams and his home a very short time before their deaths. The prosecution used many textile industry experts and representatives from Wellman and West Point Pepperell to educate the jury on fiber evidence. The prosecution used 40 charts and 350 photographs to show the tie between the fibers in Williams’ home and the victims. The prosecution used numerical probability to show that there was only 1 in 7,792 homes in Atlanta that could have had the same yellow-green Nylon fibers located in Williams’ home. The probability of all of the fibers involved being from other than Williams was even more remote. The use of probabilities for fiber evidence was unique to the Williams trial.
In trials involving fiber evidence, the fiber evidence is usually presented to corroborate other significant evidence. In the Williams trial, the prosecution used other evidence to corroborate the fiber evidence, which differed significantly from the norm. The significance of the unusual fibers, the painstaking investigation and unique presentation of evidence at trial truly showed the importance of the forensic investigation and the uniqueness of the Wayne Williams case.

Saferstein, Richard, Criminalistics: An Introduction to Forensic Science 10th ed. Upper Saddle River, NJ: Pearson - Prentice Hall