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66 AUTOMATED FINGERPRINT IDENTIFICATION SYSTEMS

AFIS system where it can be searched against the database of index fingers. As
a result, a search for the record would have been run on both the thumbs and
the index fingers to obtain an identification.
One of the selling points of AFIS is accuracy. Its vendors claim a high degree
of accuracy under certain conditions, which include good-quality inked impres-
sions on the database and good-quality impressions on the inquiry. An accuracy
rate in excess of 99% is expected for tenprint applications.

3.6 CLASSIFICATION SYSTEMS
For more than 100 years, fingerprint images were classified by the rules of the
Henry System or the American System. The introduction of AFIS technology,
however, virtually eliminated the need for fingerprint examiners to master
either of these two principal systems. Identification agencies no longer invest
enormous sums in training and certifying tenprint examiners in the most intri-
cate rules for classifying finger images. Classes on the importance of these clas-
sification systems are still provided to staff, but their usefulness in everyday
operations is on the decline.

3.6.1 THE NCIC SYSTEM
One system that does remain in active use is the classification system used by
the National Crime Information Center (NCIC). Well known to officers who
do not have immediate access to AFIS, the NCIC rules classify each finger of
a tenprint record using a combination of patterns, ridge counts, and whorl
tracing.
NCIC does not search on finger images. Instead, NCIC reports on finger
image descriptors contained in its classification system. There is no require-
ment for a digital camera, coder, or matcher. By using this relatively simple clas-
sification system, officers without immediate access to an AFIS can query NCIC
to see if their subject has a classification pattern of someone wanted in another
state. NCIC is used to tentatively identify or eliminate possible wanted suspects
or missing persons.
NCIC uses Fingerprint Classification (FPC) field codes to represent the fin-
7
gerprint image characteristics. The fingerprint class is provided on two lines,
with the first line representing the right hand and the second line the left hand.
See Table 3.1 for a list of these field codes. In addition to the fingerprint class,
there are codes for the pattern class, which are presented in Table 3.2. These
two tables are not presented for the reader to become proficient in finger-

7 See http://www.leds.state.or.us/resources/ncic_2000/ncic_2000_code_manual.htm.