NCJ Number
224402
Journal
Journal of Forensic Identification Volume: 58 Issue: 5 Dated: September/October 2008 Pages: 562-589
Date Published
September 2008
Length
28 pages
Annotation
Although the term “Level 3” detail is well known in fingerprint comparison by examiners, this article reports on a survey of examiners that shows no clear consensus on the classification, reproducibility, and individual value of Level 3 details.
Abstract
When comparing latent impressions recovered from crime scenes with exemplars from known individuals, latent fingerprint examiners focus on a range of fingerprint characteristics. These characteristics are commonly classified according to three levels of detail. Level 1 refers to the general pattern formed by the flow of ridges on the papillary surface. Level 2 refers to major ridge path deviations, known as minutiae, points of identification, or Galton characteristics. Level 3 refers to intrinsic ridge formations, which consist of the alignment and shape of each ridge unit, the pore shape, and relative pore position. A survey of 200 fingerprint examiners found disagreement among them about the classification of proposed print characteristics either into different levels or as artifacts; however, most respondents classified pores, incipient ridges, ridge edges, and ridge widths as Level 3 details, which was the expected. An unexpected finding was that characteristics such as warts, scars, or creases were also classified as Level 3 details. It was also unexpected that a high proportion of respondents classified some print features as “artifacts.” A significant variation among examiner responses was found regarding the perceived reproducibility of the proposed characteristics. Finally, no agreement was found with respect to the value to be accorded to the characteristics at issue. These survey results clearly show the need for a careful definition of the features of Level 3 print details and the weight of their contribution in the comparison process. 25 figures and 9 references