Examiner of Questioned Photographic Evidence, FBI Laboratory, Investigative Operations Support Section, Special Photographic Unit, Washington, DC
(Received 12 January 1998; accepted 21 September 1998)
The ability to identify denim trousers (e.g., “blue jeans”) from bank surveillance film through side-by-side comparison is documented herein. Individual identifying characteristics that are generated in the manufacturing process and during normal wear-and-tear may be recognized on denim trousers and in photographs depicting those trousers. These characteristics may include folds, creases, and puckering which manifest themselves as high and low areas (“ridges and valleys”) along and adjacent to the seams and hems. As the jeans are worn and washed over time, the visibility of these ridges and valleys is amplified through abrasion of the ridges, resulting in a loss of dark dye and marked tonal brightening. Given sufficient abrasion, even small ridges may exhibit sufficient contrast against the dye-rich background to be recorded on bank surveillance films, permitting a comparison with trousers recovered from suspects. The application of this technique in a case involving a series of bombings and bank robberies in Spokane. Washington, is discussed.
Paper ID: JFS14519J