d control figures for searching
prints. They limit the number of prints it is necessary to search in a
group to those prints having finals and keys closely related to the
final and key of the print being searched.

Due to the possibility of visual misinterpretation, distortion by
pressure, or poor condition of the ridge detail of the prints in file,
it is advisable to allow a margin for such discrepancies. Except in
cases where the ridge count of the final and/or key is questionable on
the print being searched, the following procedure is used:

Of the prints within any group classification, only those prints are
examined which have a final within 2 ridge counts on each side of the
final of the print being searched. For example, if the print to be
searched has a final of 17, all prints bearing a final 15 through 19
will be compared with it.

Within the final of any group classification, only those prints are
examined which have a key within 2 ridge counts on each side of the
key of the print being searched. For example, if the print to be
searched has a key of 20, all prints bearing a key of 18 through 22
will be compared with it.

In figure 352, it will be noted that there are 17 ridge counts
appearing in the right little finger and this number is used as the
final. It will also be noted that there is a loop of 24 ridge counts
in the right thumb and this number is used as the key inasmuch as it
is the first loop. In this example, the print is searched in the group
classification which has finals ranging from 15 through 19. Within
this group of finals the prints which have keys ranging from 22
through 26 are examined.

_Referencing_

Too much stress cannot be placed upon the necessity of referencing
questionable patterns, whether it be in the interpretation of the type
of pattern, the ridge count, or the tracing.

The factors which make it necessary are: variation in individual
judgment and eyesight, the amount of ink used, the amount of pressure
used in taking the prints, the difference in width of the rolled
impressions, skin diseases, worn ridges due to age or occupations,
temporary and permanent scars, bandaged fingers, crippled hands, and
amputation.

_For the highest degree of accuracy, all rolled impressions should be
checked by the plain impressions_, which generally are not distorted
by pressure. This also helps prevent error caused by the reversal or
mixing of the rolled impressions out of their pr