Class
characteristics of friction ridge prints are those characteristics
that can be possessed by more than one print. Even though a class
characteristic may be possessed by millions of prints, it can still
be of value to the individualisation or identification process. This
is so because such characteristics reduce the population of prints
that must be effectively eliminated before a condition of identity
or common source for two prints can be stated with certainty.
The
class characteristics of friction ridge skin extend to many factors
other than digit or palm, or toe or sole, and the definable pattern
type. Patterns of the same type, by definition, may appear quite
different. Thus it is not necessary to consider only whether a
pattern is a loop, for instance, but also the size of the loop, the
presence or absence of converging ridges, the ridge count, the
degree of the slope of the pattern, and even the amount of curvature
that may be present.
The individualising characteristics of friction skin are those
features of the ridges which make it possible to characterise or
identify a particular print as having been made by a particular
person. These characteristics are considered with respect to their
location, general appearance, orientation, and interrelationship
when comparison is made between two prints.
In fingerprinting, classification and identification are distinct
concepts. The two functions may and often are performed by different
personal. In some police departments, the division of labour may be
so sharp that a person skilled in fingerprint classification may not
be qualified to identify suspects based on fingerprint examinations.
The examination may be conducted manually or by computer (AFIS)
followed by visual comparison.
