This document discusses fingerprint characteristics and formation. It defines key fingerprint features like ridges, furrows, pattern area, type lines, deltas, and cores. It explains that ridges are the raised portions seen in fingerprints, while furrows are the spaces between ridges. The pattern area contains features like cores and deltas that are used in fingerprint classification and interpretation. Type lines surround the pattern area. Deltas are points where type lines diverge. The core is the center of a loop pattern. Fingerprint patterns like loops, whorls, arches are formed based on features like sufficient recurves, deltas, cores, and ridge counts.

1. FINGERPRINT
CHARACTERISTICS AND
FORMATION

2. A- RIDGE FUNCTION AND INTERPRETATION
1. RIDGE
 IS THE ELEVATED PORTION OF THE SKIN WHICH IS BLANK IN A FINGERPRINT
IMPRESSION, A MINUTE HILL-LIKE STRUCTURE OR PROTUBERANCES FOUND ON
THE EPIDERMIS OF THE SKIN CONTAINING SWEAT PORES.
2. FURROWS
 IS THE DEPRESSION OR WHITE SPACES BETWEEN THE RIDGES IN A FINGERPRINT
IMPRESSION.
3. PATTERN AREA
 IS A PART OF A LOOP OR WHORL IN WHICH APPEARS A CORE,DELTAS,AND RIDGES
WHICH WE ARE CONCERNED IN REGARD TO THE INTERPRETATION AND
CLASSIFICATION.IT IPRESENT IN ALL PATTERNS BUT IN PLAIN AND TENTED ACHES
IT IS IMPOSSIBLE TO DEFINES AS PATTERN AREA OF LOOPS AND WHORLS ARE
ENCLOSED BY THE TYPES LINES.

3. 4. TYPE LINE
-ARE TWO INNERMOST RIDGES WHICH STARTS PARALLEL DIVERGE AND SURROUND OR
TEND TO SURROUND THE PATTERN AREA.
5. DIVERGENCE
-IS THE SPREADING APART OF TWO LINES WHICH HAVE BEEN RUNNING PARALLEL OR NEABY
PARALLEL.
6. BIFURCATION
-IT IS THE FORKING OR DIVIDING OF ONE LINE INTO TWO OR MORE
BRANCHES.
7. CONVERGENCE
-IT IS THE MEETING OF TWO OR MORE RIDGES AT A CERTAIN POINT.
8. ENCLOSURE
-IT IS A SINGLE RIDGE WHICH SPLIT INTO TWO OR MORE BRANCHES AND AT CERTAIN POINT MEET
AGAIN TO FORM A SINGLE RIDGE.

4. 9. EYELET
- IT IS A SMALL ENCLOSURE
10. DOT
- IT IS A RIDGE POSSESSING A SINGLE PORE.
11. SHORT RIDGE
- IT IS A RIDGE OF A LIMITED LENGTH WITH TWO OR MORE PORES.
12. ENDING RIDGE
- IT IS THE TERMINUS OF SHORT OR LONG RIDGE

5. B- FORMATION OF DELTA AND CORE
 DELTA
-IT IS A POINT ON A RIDGE AT OR IN FRONT OF AND NEAREST THE CENTER OF THE
DIVERGENCE OF THE TYPE LINES.
A. TYPES OF DELTAS
• A BIFURCATION
• AN ABRUPT ENDING RIDGE
• A DOT
• A SHORT RIDGE
• A MEETING OF TWO RIDGES
• A POINT ON THE FIRST RECURVING RIDGE LOCATED NEAREST TO THE CENTER
AND IN FRONT OF THE DIVERGENCE OF THE TYPE LINE.

6.  CORE
-IT IS THE APPROXIMATE CENTER OF THE FINGERPRINT IMPRESSION. IT
WILL NECESSARY TO CONCERN OURSELVES WITH THE CORE OF THE
LOOP TYPEONLY.
A. RULES GOVERNING THE SELECTION OF THE CORE OF A LOOP:
B. LOOP FORMATION
1. ESSENTIAL ELEMENTS OF A LOOP
-A SUFFICIENT RECURVE
- A DELTA AND CORE
- A RIDGE COUNT ACROSS A LOOPING RIDGE

7. .SUFFICIENT RECURVE
-MAY BE DEFINED AS PART OF THE RECURVING RIDGE BETWEEN
SHOULDERS OF A LOOP,IT MUST BE FREE OF ANY APPENDAGES
ABUTTING UPON THE OUTSIDE OF THE RECURVE AT A RIGHT ANGLE.
.APPENDANGES
-SOME EXPLANATION IS NECESSARY OF THE IMPORTANCE ATTACHED
TO APPENDAGES.

8.  RIDGE COUNTING
- IT IS THE NUMBER OF RIDGES INTERVENING BETWEEN THE DELTA AND THE CORE
IS KNOWN “RIDGE COUNT” EACH RIDGES ARE COUNTED WHICH “CROSSES OR
TOUCHES” ANIMAGINARY LINE DRAWN FROM THE DELTA AND THE CORE.

9. D. ARCH FORMATION
IN PLAIN ARCHES THE RIDGES ENTER ON ONE SIDE OF THE IMPRESSION AND FLOW
OR TEND TO FLOW OUT THE ORDER SIDE WITH A RISE OR WAVE IN THE CENTER.

10. E. WHORL FORMATION
THE WHORL IS THAT TYPE OF PATTERN IN WHICH AR LEAST TWO DELTAS ARE PRESENT’S, THE
SUBDIVISION OF WHORL IS AS FOLLOW : THE PAIN WHORL, THE CENTRAL POCKET LOOP
WHORL, THE DOUBLE LOOP WHORL AND THE ACCIDENTAL WHORL.