Page 188 - Automated Fingerprint Identification Systems (AFIS)

STANDARDS AND INTEROPERABILITY 173

that the hit rate is 10%, another may respond that the rate is 15%, and yet
another may say that the rate is actually 20%. Who is wrong? Who is right? Why
is there such a difference in their answers? 6
Hit rates have different meanings for different people. A latent print super-
visor may want to include all activity since it speaks to the use of staffing
resources. A mid-level manager may be more interested in the number of cases
in which an identification has been made. The agency chief executive officer
might be more interested in the number of individuals identified and the cases
cleared. The term hit rate, or ident rate, does not specify if the rate refers to
the number of latent print identifications, the number of cases that have a
latent print ident, or the number of searches on the AFIS systems to produce
the ident. The problem centers on what should be used as the numerator and
what as the denominator in the equation that yields the hit rate. In addition,
the ways to get that numerator and denominator vary.
This section examines various factors that lead to different interpretations
of these rates and the parameters that contribute to these differences, includ-
ing the conditions under which the latent prints are captured at the crime
scene, the expertise of the officer at the scene, how the latent print is processed,
and whether the rates are based on cases or individual latent finger images.
This section also compares the latent print processing practices of two agen-
cies. Both are assumed to be staffed with competent personnel dedicated to
keeping the citizenry safe. The differences lie in the procedures they use, the
levels of expertise at key decision points, and who uses the information.
There is no national reporting center that collects latent print identification
data. As a result, there are no national standards or definitions, such as those
associated with the uniform crime report (UCR). The UCR collects specific
crime-related information from law enforcement agencies. The uniformity of
crime reporting provides some level of assurance that each reporting agency,
regardless of size, is reporting the same crime type the same way. The unifor-
mity can also allow comparisons of the effects on local reported crime due to
a change in police policies.
There is no national or industry-wide standard for latent print identifications.
In addition to differences in rate interpretation by staff within an agency, there
are differences in counting latent print identifications between agencies. The
method of counting does not negate the value of the latent print identification,
but it may mask opportunities to replicate true increases in the number of
identifications.

6 This chapter assumes the continuity of evidence is maintained throughout all transactions.