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 disease , 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 proper order. For the

same reason, as much of the counting and tracing should be done in the

plain impressions as it is possible to do.



If there is any doubt as to which of two or more classifications

should be assigned to a given pattern, it is given the preferred

classification and reference searches are conducted in all other

possible classifications. For example, if on a print with the

preferred classification



1 A

----

1 Aa



it is questionable whether the left middle finger should be a plain

arch, a tented arch, or a radial loop, the print is searched in the



1 A

----

1 Aa



group, and reference searches are conducted in the



1 A

----

1 At



and



1 A

----

1 Ar



groups. For further illustration, a print is given a preferred primary

classification of



1,

-

1



although the ridge detail on the right thumb is so formed as to

resemble a whorl. The search is completed first in the preferred



1

-

1



primary classification and a reference search is then conducted in the



1

--

17



primary.



All ridge counts that are line counts, i.e., when one more or one

less count would change the designation of the loop from I to O or

from S to M, etc., must be searched in both groups. For example, in a

print classified



16 M 1 U III 10,

---------------

M 1 U III



if the ridge count of the right middle finger is 10 and the count in

the right thumb is 16 (as indicated by the key), the print would be

searched first as classified, then reference searches would be

conducted in the following groups:



M 1 U IOI, L 1 U III, L 1 U IOI

--------- --------- and ---------

M 1 U III M 1 U III M 1 U III



When there is doubt concerning the tracing of a whorl, it should be

treated in the same fashion. For example, if in the classification



O 5 U

------

I 17 U



doubt existed as to whether the tracing of the right thumb might not

be a meeting tracing, the print would be searched as classified, and a

reference search would be conducted in



M 5 U.

------

I 17 U



If there is no doubt concerning the ridge count used for the final, it

is enough to search out of the group only those prints containing a

final within 2 ridge counts on each side of the final on the print

being searched. When, however, there is doubt concerning the ridge

count of the final, the print should be searched 2 ridge counts on

each side of the two extremes of possibility. For example, if it were

possible for a final to be 6, 7, 8, or 9 ridge counts, the print

should be searched through that part of the group bearing finals of

from 4 through 11.



The above explanation pertaining to the final also applies to the key.



All prints bearing amputations should be referenced to the necessary

files containing prints other than amputations for reference searches.



In instances where only one finger is amputated, reference searches

are conducted in all possible classifications, including all possible

ridge counts or tracings. For example, a print containing the

classification:



AMP



4 S 1 U III 6

-------------

S 1 U III



with the right index finger amputated, the left index finger being an

ulnar loop, would be searched first in the amputation group for the

classification, then reference searches would be conducted in the

following groups in the nonamputation files:



S 1 U III S 1 T II S 17 W III

--------- --------- ----------

S 1 U III S 1 U III S 1 U III



S 1 U OII S 1 R III S 17 W MII

--------- --------- ----------

S 1 U III S 1 U III S 1 U III



S 1 A II S 1 R OII S 17 W OII

--------- --------- ----------

S 1 U III S 1 U III S 1 U III



All prints bearing unprinted or badly crippled fingers are filed in

the nonamputation files, and reference searches are conducted in the

amputation group.



For the purpose of determining if it is feasible to conduct reference

searches in all possible classifications, the method of referencing

amputations is applied to completely scarred patterns (Chapter titled

Scarred Patterns--Amputations--Missing at Birth). For example, a

print bearing the preferred classification:



13 O 17 W OOO 14

----------------

L 17 U OOI



with the left middle finger completely scarred, the right middle

finger being an ulnar loop with a ridge count of 13, would be searched

first in the group for that classification, then reference searches

would be conducted in the following groups:



O 17 W OOO O 17 W O 19 W OOO

---------- ------- ----------

L 17 U OII L 17 Ur L 17 U OOI



O 17 W O 19 W OOO

------- ----------

L 17 Ua L 17 U OII



O 17 W O 19 W OOO

------- ----------

L 17 Ut L 17 U OMI



The referencing of partial scars is a problem in which many factors

are present. A full explanation of the scars, their preferred

classifications and their references is made in the chapter,

Classification of Scarred Patterns--Amputations--Missing at Birth.



When the age extension is utilized and a Reference group and a

Presumptive Dead file are maintained, it is suggested that a general

allowance of 5 years be considered to allow for a discrepancy in

prints bearing the ages of 50 years or older.



In the files of the Federal Bureau of Investigation the various age

groups are as follows:



1-54 Regular file.

55-74 Reference file.

75 and over Presumptive Dead file.



Reference searches for the preceding groups are conducted in the

following manner:



50-54 Referenced to Reference file.

70-74 Referenced to Presumptive Dead file and Regular file.

75-79 Referenced to Reference file and Regular file.

80 and older Referenced to Regular file only.



If no age is given, it should be searched first in the regular file

and reference searches should be conducted in the Reference group

and the Presumptive Dead file.



When separate male and female files are maintained, there may be doubt

as to the sex of a subject due to a discrepancy between the sex

indicated and the name and the description and picture. In such case

try to determine the sex from the description and the size of the

prints, then reference the print to the other file. A Photostat copy

can be made and placed in the other file until the true sex can be

determined.