Examination of Firearms Review: 2007 to 2010 - Interpol

Studies on general characteristics
A study on two populations (two cities in the same country) using a classification and
regression tree algorithm is presented (103); here, the goal is to use only finger
number and general pattern for the prediction of a population that an individual
belongs to. The classification is expected to be correct, when using all ten fingers,
90.8% of the time if all ten general patterns of the individual are left loops or whorls
with only the right ridge count, and 98.4% if all general patterns of the individual are
whorls with two ridge counts.
Frequencies of various dermatoglyphic measures for males and females of Kavalan
(one of the Taiwan aboriginal populations) are reported by Chen et al. (104). These
include general patterns, identical patterns on the corresponding fingers of the right
and left hand, corresponding patterns on all fingers of one hand and on both hands,
ridge counts, atd angle, tPD, palmar interdigital, thenar and hypothenar patterns,
different combinations of palmar interdigital, thenar and hypothenar patterns on left
and right corresponding hands, angles and simian line on palms.
Ridge density in a sample of Spanish Caucasians is also reported (105). Ridge
densities of 16/25 mm 2 or less in the radial area considered are more likely to be of
male origin when using equal priors, while ridge densities of 17/25mm 2 or more are
more likely to be of female origin; for the ulnar area these numbers are of 14/25mm 2
or less for males and 17/25mm 2 or more for females. Sex-differences in an Indian
population are reported by Nayak et al. (106) ; here, a mean ridge count of 12/25mm 2
or less is more likely to be of male origin while a greater ridge count is more likely to
be of female origin. Ridge densities for a South-Indian population are reported by
Gungadin (107), where 13/25mm 2 or less are more likely if the impression is of male
origin, while 14/25mm 2 or more are more likely if the impression is of female origin.
Nayak et al. also report on ridge densities for Chinese and Malaysian populations
(108, 109) ; here, in the Chinese population, a ridge density of less than 12/25mm 2 is
more likely to be of male origin while ridge densities above 13/25mm 2 are more likely
to be of female origin. In Malaysian subjects, it is a ridge density of 11/25mm 2 or less
that is more likely to be of male origin, and a fingerprint with a ridge density of more
than 13/25mm 2 is more likely to be of female origin. The relationship between ridge
density and stature has however not been investigated. Furthermore, fingerprint
classification and gender distribution was studied in a South Indian population (110),
and no difference by sex between general patterns was highlighted in this study. The
reason for the observed difference between sexes as to ridge density is the object of
a letter to the editor (111). Data in relation to the general pattern present in the feet
have also been published (142). Duta (112) shows the selectivity of the hand-shape
as a biometric.
Creases
An automated extraction and comparison procedure for palmar flexion creases,
carried out on a sample of 100 palms with 10 images of each one, achieves a
genuine acceptance rate of 100%, for a false acceptance rate of 0.0045% (113),
thereby illustrating the selectivity of this characteristic. Crease detection has been
investigated by Zhou and co-workers (114), with particular application to the
fingerprints of elderly people. The stability of creases is investigated, and matching
based on creases and minutiae carried out. Also, the creases are used to remove
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