The Science of Fingerprints: Classification and Uses

by United States. Federal Bureau of Investigation

CHAPTER V

Classification of Scarred Patterns—Amputations—Missing at Birth

Classification of scarred patterns

Emphasis should be placed upon the necessity for fully referencing all scarred patterns. In connection with their proper classification, the following rules should be observed:

● When an impression is so scarred that neither the general type of pattern nor the ridge tracing or count can be determined with reasonable accuracy, the impression should be given both the general type value and the subclassification value of the corresponding finger of the other hand.

● When an impression is partially scarred, i.e., large scars about the core so that the general type cannot be determined with reasonable accuracy, but the ridges allow reasonably accurate subclassifications by ridge tracings or counting, the impression should be given the primary value of the pattern of the corresponding finger and the subclassification value as indicated by the ridges of partially scarred impressions.

● When an impression is partially scarred and the general type of pattern can be determined with reasonable accuracy, but the ridges cannot be traced or counted so as to fall within the proper subsecondary classification, the impression should be given the ridge count or tracing value of the corresponding finger of the other hand, if the corresponding finger is of the same general type. If the corresponding finger is not of the same general type, the scarred impression should be given the probable value and referenced to all other possibilities.

● When an impression is so scarred that neither the general type of pattern nor the ridge tracing or count can be determined with reasonable accuracy, and it so happens that the corresponding finger of the other hand is similarly scarred, both patterns are given the arbitrary value of whorls with meeting tracings.

In figure 355, the pattern is entirely obliterated. It could have been a small whorl, a small ulnar or radial loop, an arch, or a tented arch. If the opposite finger were an arch or tented arch or whorl, this impression would be classified as arch, tented arch, or whorl (with the same tracing). If the opposite finger were a small-count loop, this would be classified as a loop of the same count. If the opposite finger were a large-count loop, this impression would be given the count of the opposite finger even though it could never have had that count. If the opposite finger were scarred in the same fashion or were amputated or missing, both impressions would be classified as whorls with meeting tracings.