Supplementary Notes
Supplementary Notes
Supplementary Notes
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SUPPLEMENTARY NOTES
RIDGE CHARACTERISTICS
“Galton Details”
“Minutial Points”
“Points of Identity”
“Minutiae”
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Ridge Characteristics Diverging Ridges
Identification of fingerprints relies on pattern matching Are two ridges running side by side and
followed by the detection of certain ridge suddenly separating, one ridge going one way
characteristics, also known as Galton details, points of and the other ridge going another way.
identity, or minutial points with a reference print,
usually an inked impression of a suspects print.
IMPORTANT TERMS:
The two
outermost
ridges which Converging ridge
tend to A ridge formation whose closed end is angular
surround the and serves as a point of convergence, usually
pattern area. pointed and abrupt forming a “V” shape.
The basic
boundaries of most fingerprint patterns.
Area of
divergence
Crease
Ridges which are thin, usually straight narrow
white lines running transversely, or formed side
to side, across the print, causing the puckering
of the ridges.
double bifurcation
Short ridge
a ridge that is insufficient or limited in length
Series of Bifurcations
other than the fragment.
Bifurcations that appear in tandem or group.
Dot Ridge
Spur or hook ridge Any dot or point that can be observed inside a
A bifurcation with one short ridge branching fingerprint pattern.
off a longer ridge.
Ridge Ending
an abrupt end of any ridge formation.
Staple
a single recurving ridge on the center of the
pattern area. It can be located along the
looping ridges.
Ridge Brake
Enclosure
A bifurcation which does not remain open but
in the legs of the bifurcation, after running
alongside for a short distance, come together to
form a single ridge once more.
Envelop
A single recurving ridge enclosing one or more
bars, short or dot ridge. Incipient Ridges (Nascent ridges)/ Rudimentary
Ridges that were never counted because they
are only the result of dirt, blurred impressions,
dirty fingerprint paraphernalia and other
factors, the short narrow and badly formed
ridges found between two well formed ridges.
Overlap
An overlap is where two ridges ends meet and Dissociated Ridges
overlap on a bias. are usual ridge structure having a no well
defined pattern, the ridge are extremely short,
they appear like series of patches caused by
disturbance during developmental process at
early fetal life of an individual.
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FINGERPRINT PATTERNS
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CATEGORIES /FAMILIES/ GENERAL PATTERN TYPES
OF FINGERPRINTS:
4. Accidental Whorl - 3%. 4. Ulnar Loop (U) - a fingerprint pattern where the
THE 8 FINGERPRINT PATTERNS direction of the ridges flows towards the little finger
side of either right or left hand. The term Ulnar came
1. Plain arch (A) - a pattern in which the ridges from the Greek term “Ulna” which means little finger
enter on one side of the pattern then flow bone.
toward the other side, with a rise at the center.
“The simplest of all patterns.”
1. It must have a delta; 1. There must be atleast one recurving ridge that
rises at right angle.
2. It must have a core;
2. It must have atleast two deltas
3. It must have a recurving ridge that passes
between the core and delta; and 3. There must be no whorl ridge that touches the
imaginary line drawn between the two deltas.
4. It must have ridge count of atleast one.
OTHER TYPES OF LOOP:
7. Double Loop Whorl (D)
1. Plain Loop – the ridges in this pattern make a backward turn A fingerprint pattern consisting of two separate
arranging themselves in the form of a hairpin or staple. and distinct loop formations with two sets of
2. Converging Loops – the ridges of this pattern converge sharply to shoulders, and two deltas.
give the pattern a possible whorl like appearance.
Also called Composite Pattern.
3. Nutant Loop – the ridges of this pattern conform to the
explanation of the plain loop but additionally the looping ridges
bent over and drops towards the delta.
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CORE & DELTA; RIDGE COUNTING & TRACING
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CORE & DELTA - Focal Points of Fingerprints RULES IN LOCATING DELTA
- is also known as Fingerprint terminus. RULE 1 – The bifurcation that is open towards the core
is chosen as the delta.
The two fingerprint terminus:
1. Bifurcation
2. Dot
3. Meeting of two ridges
4. Ending ridge
5. Starting ridge
6. Looping ridge (where no other choice of delta)
RULE 4 – When there is a choice between two or more
CORE (inner terminus) possible deltas (except bifurcation), the delta nearest to
is a point on the ridge formation usually the core is chosen.
located at the approximate center or heart of
the pattern.
RULES OF RIDGE COUNTING AND TRACING 2. An abrupt ending of ridges is given one
ridge count.
Ridge Counting
3. Ridge that bifurcates
is the process of counting the ridges that touch
or cross an imaginary line drawn between the Ridge Tracing
core and the delta of a loop pattern.
The process of tracing the ridges intervening
RULES IN RIDGE COUNTING between the tracing ridge (flows from the left
delta to the right delta) and the right delta in a
1. In a loop fingerprint pattern, locate the delta
whorl pattern.
and core.
RULES OF RIDGE TRACING
2. Draw an imaginary line between the core and
delta. 1. In a whorl pattern, look for the left delta and
trace towards the front of the right delta.
3. Count all ridges which touch or cross the
imaginary line drawn between the core and 2. When the ridge being traced abruptly ends,
delta. In actual use of fingerprint card for drop to the next ridge just below the original
classification, the lens is guided by a red line tracing ridge and continue the tracing until it
shown on the disk. reaches the point nearest to the right delta.
4. Incipient ridges, puckering, disssociated and 3. When the left delta is a dot, the same
creases are NOT counted. procedure in No. 1 shall be followed.
5. Fragments and dot ridges are counted as ridges 4. When the ridge that is being traced is a
only if they appear as thick as the surrounding bifurcation, always follow the lower branch
ridges. until tracing is completed.
6. DO NOT include in your counting the delta 5. Determine whether the tracing ridge flows
and core. inside (above) or outside (below) the right
delta.
6. Draw and imaginary line between the tracing
ridge (refers to the left delta that was moved
towards the right delta) and the right delta and
count the intervening ridge that touch or cross
it.
Examples:
RIDGES SUBJECT TO RIDGE COUNTING
3 RIDGE COUNT
1. Envelop
2. trifurcation
2 RIDGE COUNT
1. An island/lake/eye, and enclosure.
3. Bifurcation of ridges
4. Converging ridge
1 RIDGE COUNT
1. A short ridge, long ridge, dot ridge,