The Science of Fingerprints - Part 14
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Part 14

Thus, if a radial loop appears in the right thumb, the small letter "r" would be brought up in the numerator column of the cla.s.sification formula and placed just to the left of the capital letter representing the index finger. Similarly, if an arch or tented arch or a radial loop would appear in the middle, ring, or little finger of the hand, the small letter representing such a pattern would be placed on the cla.s.sification line to the right of the secondary in the numerator column if the letter is present in the right hand, and in the denominator column if in the left hand. When two or more small letters of the same type occur immediately adjacent to each other, they are indicated thus:

1 rU-2a 1 aTa-a.

------- and ------- 1 tU3a 1 tA2at

The small-letter groups are of vital importance to the cla.s.sification system, as they are of relatively infrequent occurrence, const.i.tuting approximately 7 to 10 percent of all patterns. Generally speaking, since these patterns are of such rare occurrence, their very presence often enables the cla.s.sifier to dispense with the usual subsecondary cla.s.sification and the major division which in the majority of cases are used in the larger groups.

THE SUBSECONDARY CLa.s.sIFICATION (GROUPING OF LOOPS AND WHORLS): In cla.s.sifying prints it is necessary to subdivide the secondary groups.

This is accomplished by grouping according to the ridge counts of loops and the ridge tracings of whorls. The first of the groups filed in order, which it will be necessary to so subdivide, would ordinarily be the

1 R --- 1 R

group where no small letters appear. The Federal Bureau of Investigation, however, has found it necessary to extend this division to many of the small-letter groups which become c.u.mbersome. The subsecondary is placed on the cla.s.sification line just to the right of the secondary. Ridge counts are translated into small and large, represented by symbols I and O. The whorl tracings are brought up as I, M, or O denoting inner, meeting or outer ridge tracings of the whorl types. Only six fingers may be involved in the subsecondary--numbers 2, 3, 4, 7, 8, and 9.

A ridge count of 1 to 9, inclusive, in the index fingers is brought up into the subsecondary formula as I. A count of 10 or more is brought up as O. In the middle fingers a count of from 1 to 10, inclusive, is brought up as I, and 11 or more is O. In the ring fingers a count of from 1 to 13 is brought up as I, and 14 or more is O. A loop subsecondary could appear in the cla.s.sification formula as

OIO.

--- IIO

a.n.a.lyzing this example of a subsecondary, one will know that in the index, middle, and ring fingers of the right hand there are counts of over 9, under 11, and over 13, while in the left hand there are in the index, middle, and ring fingers, counts of under 10, under 11, over 13, respectively. The subsecondary cla.s.sification, therefore, relates to the groupings of the prints, and no difficulty should be experienced in ascertaining whether the I and O arrangement in the subsecondary relates to loops or whorls when a.n.a.lyzing a cla.s.sification, because this information can be obtained from the primary cla.s.sification. Figure 350 is an example ill.u.s.trating the subsecondary in addition to other divisions of the cla.s.sification formula.

[Ill.u.s.tration: 350]

LEAVE THIS s.p.a.cE BLANK

s.e.x +--------------+

__________

FBI No.

RACE +--------------+

LAST NAME FIRST NAME MIDDLE NAME

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

----------------------------------+---------- SIGNATURE OF PERSON

CONTRIBUTOR

ALIASES

HT.

WT.

FINGERPRINTED

AND ADDRESS

(IN.)

_____

____

DATE OF -----------------------------

BIRTH RESIDENCE OF PERSON

__________ FINGERPRINTED

HAIR

EYES

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

--------------------------------------------- OCCUPATION

ARREST NUMBER

LEAVE THIS s.p.a.cE BLANK

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

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

SCARS AND MARKS

PLACE OF

BIRTH

26 5 R OOO 12

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

CLa.s.s__________________________ -----------------------------

CITIZENSHIP

12 W MOI SIGNATURE OF OFFICIAL

DATE

_

TAKING FINGERPRINTS

_

CHECK IF

NO CRIMINAL

REF.___________________________

RECORD IS

DESIRED

--------------------------------------------------------------------------- 1. RIGHT THUMB

2. RIGHT INDEX

3. RIGHT

4. RIGHT RING

5. RIGHT LITTLE

MIDDLE

26

12

0

17

12 [Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

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

R

W

--------------------------------------------------------------------------- 1. LEFT THUMB

2. LEFT INDEX

3. LEFT

4. LEFT RING

5. LEFT LITTLE

MIDDLE

I

M

18

I

15 [Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

--------------------------------------------------------------------------- W

W

/

W

/ ---------------------------------------------------------------------------

The chart, figure 351, will ill.u.s.trate the manner in which the ridge counts are translated into the symbols I and O so they may be grouped and sequenced with the whorl tracings I, M and O.

THE MAJOR DIVISION: The major division is placed just to the left of the primary in the cla.s.sification formula. Where whorls appear in the thumbs the major division reflects the whorl tracings just as the subsecondary does. For example, a major division of I over M in the primary 5 over 17 would reflect an inner-traced whorl over a meeting-traced whorl in the thumbs. Where loops appear in the thumbs, however, a table is used to translate the ridge counts into the small, medium, or large groups, designated by the letters S, M, L. An expanding table is used for the right thumb when large-count loops appear in the left thumb, as shown in the chart (fig. 351). This table is used because it affords a more equitable distribution of prints as a whole, for filing purposes within the groups indicated.

[Ill.u.s.tration: 351. Cla.s.sification Chart]

--RIGHT HAND-- --------------------------------------------------------------------------- R THUMB

R INDEX

R MIDDLE

R RING

R LITTLE --------------------------------------------------------------------------- WHEN LEFT THUMB

1-9 = I

1-10 = I

1-13 = I

IS 16 OR LESS

10 AND OVER = O

11 AND OVER = O

14 AND OVER = O

1-11 = S

12-16 = M

17 AND OVER = L

--------------------RIDGE COUNT OF SECOND SUBSECONDARY--------------------- WHEN LEFT THUMB

1-5 = S

1-8 = S

1-10 = S

IS 17 OR OVER

6-12 = M

9-14 = M

11-18 = M

1-17 = S

13 AND OVER = L

15 AND OVER = L

19 AND OVER = L

19-22 = M

23 AND OVER = L

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

--LEFT HAND-- --------------------------------------------------------------------------- L THUMB

L INDEX

L MIDDLE

L RING

L LITTLE --------------------------------------------------------------------------- 1-11 = S

12-16 = M

17 AND OVER = L

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

Table for major divisions of loops:

_Left thumb denominator_ _Right thumb numerator_

{ 1 to 11, inclusive, S (small).

1 to 11, inclusive, S (small) { 12 to 16, inclusive, M (medium).

{ 17 or more ridges, L (large).

{ 1 to 11, inclusive, S (small).

12 to 16, inclusive, M (medium) { 12 to 16, inclusive, M (medium).

{ 17 or more ridges, L (large).

{ 1 to 17, inclusive, S (small).

17 or more ridges, L (large) { 18 to 22, inclusive, M (medium).

{ 23 or more ridges, L (large).

The fingerprint card appearing in figure 352 shows a major division of L over L, which is obtained by counting the ridges (24 in the right thumb and 18 in the left thumb) which, according to the table, is translated into L in both thumbs.

THE FINAL: It is, of course, desirable to have a definite sequence or order of filing the prints within the subdivided groups. This order is attained through the use of the final, which is based upon the ridge count of the loop in the right little finger. It is indicated at the extreme right of the numerator in the cla.s.sification. Note figure 352.

If a loop does not appear in the right little finger, a loop in the left little finger may be used. It is then indicated at the extreme right of the denominator (fig. 353). If no loops appear in the little fingers, a whorl may be used to obtain a final, counting from left delta to core if in the right hand and from right delta to core if in the left hand. If there are two or more cores (usually applies to accidental whorls), the ridge count is made from left delta (right hand) or right delta (left hand) to the core which is the least number of ridges distant from that delta. An exception is made in the case of the double loop. The double loop is counted from the delta to the core of the upright loop. Where loops of a double loop are horizontal, the nearest core is used. Should both little fingers be a or t, no final is used. The use of a whorl in a little finger for a final is required only in connection with a large group or collection of prints, such as the 32 over 32 primary.

[Ill.u.s.tration: 352]

LEAVE THIS s.p.a.cE BLANK

s.e.x +--------------+

__________

FBI No.

RACE +--------------+

LAST NAME FIRST NAME MIDDLE NAME

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

----------------------------------+---------- SIGNATURE OF PERSON

CONTRIBUTOR

ALIASES

HT.

WT.

FINGERPRINTED

AND ADDRESS

(IN.)

_____

____

DATE OF -----------------------------

BIRTH RESIDENCE OF PERSON

__________ FINGERPRINTED

HAIR

EYES

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

--------------------------------------------- OCCUPATION

ARREST NUMBER

LEAVE THIS s.p.a.cE BLANK

LLL -----------------------------

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

LMM SCARS AND MARKS

PLACE OF

BIRTH

24 L I R O O O 17

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

CLa.s.s__________________________ -----------------------------

CITIZENSHIP

L I R O O O SIGNATURE OF OFFICIAL

DATE

_

TAKING FINGERPRINTS

_

CHECK IF

NO CRIMINAL

REF.___________________________

RECORD IS

DESIRED

--------------------------------------------------------------------------- 1. RIGHT 24

2. RIGHT 13

3. RIGHT 31

4. RIGHT 21

5. RIGHT 17 THUMB

INDEX

MIDDLE

RING

LITTLE

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

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

R

--------------------------------------------------------------------------- 1. LEFT 18

2. LEFT 16

3. LEFT 13

4. LEFT 18

5. LEFT 20 THUMB

INDEX

MIDDLE

RING

LITTLE

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

--------------------------------------------------------------------------- /

R

/

/

/ ---------------------------------------------------------------------------

THE KEY: The key is obtained by counting the ridges of the first loop appearing on the fingerprint card (beginning with the right thumb), exclusive of the little fingers which are never considered for the key as they are reserved for the final. The key, no matter where found, is always placed to the extreme left of the numerator of the cla.s.sification formula (fig. 353).

_Extensions_

THE SECOND SUBSECONDARY CLa.s.sIFICATION: When a group of fingerprints becomes so large that it is c.u.mbersome and unwieldy, even though fully extended, it can be subdivided further by using a second subsecondary division, which is brought up into the cla.s.sification formula directly above the subsecondary, and for which the symbols S, M and L are used. The following table is used:

_Index_ _Middle_ _Ring_

1 to 5, inclusive, S. 1 to 8, inclusive, S. 1 to 10, inclusive, S.

6 to 12, inclusive, M. 9 to 14, inclusive, M. 11 to 18, inclusive, M.

13 or more, L. 15 or more, L. 19 or more, L.

If this table is referred to, a study of figure 352 will demonstrate the use of the second subsecondary.

[Ill.u.s.tration: 353]

LEAVE THIS s.p.a.cE BLANK

s.e.x +--------------+

__________

FBI No.

RACE +--------------+

LAST NAME FIRST NAME MIDDLE NAME

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

----------------------------------+---------- SIGNATURE OF PERSON

CONTRIBUTOR

ALIASES

HT.

WT.

FINGERPRINTED

AND ADDRESS

(IN.)

_____

____

DATE OF -----------------------------

BIRTH RESIDENCE OF PERSON

__________ FINGERPRINTED

HAIR

EYES

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

--------------------------------------------- OCCUPATION

ARREST NUMBER

LEAVE THIS s.p.a.cE BLANK

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

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

SCARS AND MARKS

PLACE OF

BIRTH

22 M 11 U OOO

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

CLa.s.s__________________________ -----------------------------

CITIZENSHIP

L 6 U OMI 13 SIGNATURE OF OFFICIAL

DATE

_

TAKING FINGERPRINTS

_

CHECK IF

NO CRIMINAL

REF.___________________________

RECORD IS

DESIRED

--------------------------------------------------------------------------- 1. RIGHT THUMB

2. RIGHT INDEX

3. RIGHT

4. RIGHT RING

5. RIGHT LITTLE 22

11

MIDDLE 19

O

O

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

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

W

W --------------------------------------------------------------------------- 1. LEFT THUMB

2. LEFT INDEX

3. LEFT M

4. LEFT RING

5. LEFT LITTLE 18

10

MIDDLE I

I

13

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

[Ill.u.s.tration]

--------------------------------------------------------------------------- /

/

W

W

/ ---------------------------------------------------------------------------

WCDX EXTENSION: In the extension used in the Federal Bureau of Investigation for the large whorl groups, the type of whorl is designated by the symbols W, C, D, or X for the index fingers and w, c, d, or x for all other fingers, according to its cla.s.sification as defined in figure 354. These symbols are used for subcla.s.sification purposes only and are brought up into the cla.s.sification formula directly above the subsecondary in their respective positions, the right hand being the numerator, the left hand being the denominator.

SPECIAL LOOP EXTENSION: In the all-loop group

(1R-U) ------ (1R-U),

the following special loop extension may be used, utilizing the ridge counts in fingers Nos. 2, 3, 4, 7, 8, 9, and, if necessary, No. 10:

_Ridge Counts_ _Value_