NCJ Number
95092
Date Published
1982
Length
8 pages
Annotation
Discussion focuses on classifying fingerprints, fingerprints as positive means of identification, and comparing prints.
Abstract
During the past 100 years, fingerprinting has become recognized as a method to determine positively the identity of anyone who has been fingerprinted and whose prints have been maintained on file. Generally, fingerprints are classified into three types of Galton-named patterns: loops, whorls, and arches. The ridge characteristics of each fingerprint are unique and permanent. Fingerprints may be inked prints or latent (i.e., chance impressions, such as those left at a crime scene). Latent prints can be developed with colored powder and a brush and can be preserved by covering them with transparent plastic. Latent prints on nonporous surfaces or impressed in paint or blood can be preserved only on the article itself or photographically. On surfaces that absorb moisture, a chemical should be used to develop prints. Ninhydrin, silver nitrate, and iodine fuming provide methods for developing latents containing amino acids, salt, and fat or oil, respectively. All potentially crime-related objects should be examined for latent prints. The area needed to identify any unknown latent print with a known inked print is very small and depends upon the number of points of identity in common in a given area. Only officers or investigators experienced in fingerprints should be allowed to work on latent prints, and only those with considerable experience in all phases of fingerprinting should attempt to qualify as expert witnesses. The value of a file of inked fingerprints depends on the expertise of the agency or officers who contribute to it. Generally, little training is needed to enable an officer to take good prints. The science of fingerprinting remains the only infallible means of positive identification. Figures are included.