Fingerprint - Everything You Need To Know About Fingerprints

FINGERPRINTS
By – Swaroop S. Sonone

INDEX
• Module I: History and Classification of Fingerprints
• Module II: Types of fingerprints and Methods of Developing Fingerprints
• Module III: Other Methods of Developing Fingerprints
• Module IV: Comparison and Analysis of Fingerprints
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Mr. Swaroop S. Sonone, M.Sc. Forensic Science

MODULE I: CONTENTS
• History and Development of Fingerprints.
• Formation of Ridges, Pattern Types, Pattern Areas.
• Classification of fingerprints-
1. Henry System of Classification
2. Single digit Classification
3. Extension of Henry System.
• Search of Fingerprints.
• Fingerprint Bureau.
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GENERAL INTRODUCTION TO FINGERPRINTS
• A Fingerprint is an impression left by the friction ridge of a human finger.
• The recovery of partial Fingerprints from a crime scene is an important method of Forensic
science.
• The analysis of Fingerprints, palm print and foot printing are called Dermatoglyphics.
• Fingerprint is one of the most important criminal investigation tools due to their two
significant features- uniqueness and persistence.
• The unique features of friction ridge skin persist from before birth, i.e. during fetal
development to the decomposition after death.
4

HISTORY & DEVELOPMENT OF FINGERPRINTS
• The earliest detailed reference is found in Kausalya’s “ Arthashastra” which was written about
2300 years ago. It is presumed that they knew about the persistence and individuality of
fingerprints at that time.
• The history of fingerprints has it is origin in Asia. Old documents show that during
Hammurabi’s reign in ancient Babylon , finger seals were used on contact.
• There is more definite proof of Chinese using finger impression is sales on documents and
contracts.
• The first of profound the theory that the arrangement of friction ridges is never duplicate in two
individuals was JCA Mayer of Germany in 1788.
• In 1823 professor J. E. Purkinge published a thesis in which he described friction ridges pattern
and classified the fingerprint into 9 categories.
• It was in 1858 when sir William Herschel British administrator in Bengal started the practice of
recording handprints of natives on the contract that modern fingerprints science came to life.
5

HISTORY & DEVELOPMENT OF FINGERPRINTS
• In 1874 Dr. Henry Fauld working at Tsukiji hospital in Tokyo, observes the designs of a human
fingerprint on Japanese pots.
• Sir Francis Galton an English scientist and a cousin of Darwin in 1892 wrote the first textbook
“fingerprints” in which he scientifically established that no two fingerprints are alike and
describe a system of classification of the fingerprints.
• Sir Edward Henry while working in Indian as an inspector general of police in Bengal develop
an interest in work of Hershel and Galton and give a more workable system of classification
which was first developed in India in 1897.
• A Significant contribution was made by the Bengal police officers Khan Bahadur Aziz Ul Haque
and Rai Bahadur Hem Chandra Bose described the 10 digit classification system or primary
classification system. 6

FORMATION OF RIDGES
• The basics of Fingerprint development lies in the developmental biology or embryology. The
fingerprints of an individual starts its development in the mother's womb.
• The development of friction ridges starts during the initial weeks of gestation and can easily
studied with estimated gestational age (EGA) of the foetus. The hands of the foetus start to
develop from 5-6 weeks EGA while the fingers appear around 6-7 weeks EGA.
• From 7-8 weeks EGA volar pads start to develop on palm (interdigital pads followed by thenar
and hypothenar pads) and on the fingertips (apical pads).
• Volar pads are transient swellings of mesenchymal tissue under the epidermis on palmar
surfaces of foetus hand.
• These volar pads remain well rounded during their rapid proliferation at about 10 weeks EGA.
Then they start to regress from 11 weeks EGA and completely get merged with the contours of
fingers by week 16 EGA, this phenomenon is described as the volar pad regression.
• At around 10-10.5 weeks EGA, basal layer (middle layer of skin) which is scrunched between
the epidermis (outer layer of skin) and dermis (inner layer of skin) starts to proliferate rapidly
than other two.
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FORMATION OF RIDGES
• The undulations of basal layer in embryo of 10-13 weeks EGA leads to form folds of epidermis
into dermis. These folds are known as primary ridges. The formation of primary ridges on fingers
and palm are followed by toes and the sole.
• At about 15 weeks EGA, primary ridges start to grow in two directions- the downward
penetration of sweat gland and upward growth of new cells.
• These primary ridges mature, extend deeper into the dermis and becomes permanently
established by 16 weeks EGA. Because of their deeper establishment at the interface between
dermis and epidermis, fingerprint patterns cannot be destroyed by superficial skin injuries.
• When these developing ridges becomes sandwiched between existing ridges, ending ridges get
formed. Even due to differences in the timing of development and slight variation in mechanical
stress could significantly affect the location of minutiae.
• Between 15-17 weeks EGA, secondary ridges appear between the primary ridges on underside of
the epidermis and downfolds of basal epidermal layer leads to increase the surface area of
attachment to the dermis.
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FORMATION OF RIDGES
• The secondary ridges mature by 24 weeks EGA. By week 23 EGA, bridges between the apex of
primary dermal ridges and secondary dermal ridges i.e. dermal papillae start to form and
continue to develop even into adulthood.
• Thus the raised portion of the skin are friction ridges, which leave impression over the surfaces
as fingerprints and the portion between the ridges called furrows collaboratively forms the
Friction Skin.
• The whole area of palm, fingers, sole, and toes get completely covered with friction skin during
the third or fourth month of fetal development.
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PATTERN TYPES
• Friction ridges over the surface of fingers and thumbs form various but unique patterns that
are known as Fingerprint Patterns.
• Even the identical twins have a different friction ridge configuration.
• Fingerprint patterns are categorized into three main groups of patterns with several sub-
groups:
1. Arch
2. Whorl
3. Loop
• Arch - The ridges enter on one side of the impression and flow or tend to flow out the each other
with a rise or wave in the centre.
1. Plain arch- Appearance of rising or wavy ridge in the centre.
2. Tented arch- Ridges at the centre form an angle of 90 degrees or less, or form an up thrust
(ending ridge) at 45 degrees or more with the horizontal plane.
10

PATTERN TYPES
• Loop - One or more ridges enter on the either side of the impression; recurve, touch or pass an
imaginary line drawn from the delta to the core, and terminate or tend to terminate on or toward
the same side of the impression from where such ridge or ridges are entered.
1. Ulnar loop- Pointing towards the ulna bone or little finger.
2. Radial loop- Pointing towards the radius bone or thumb.
• Whorl - A type of pattern in which at least two deltas are present with a recurve in front of each.
1. Plain whorl- An imaginary line drawn from one delta to another must touch or cross at least
one of the recurving ridges of the inner pattern.
2. Central pocket loop- An imaginary line drawn from one delta to another must not touch or
cross at least one of the recurving ridges of the inner pattern.
3. Double loop- Two separate loop formations with distinct set of shoulders.
4. Accidental- combination of two or more pattern types except plain arch.
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PATTERN TYPES
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PATTERN AREA
• The pattern area is the part of a loop or a whorl pattern in which include the core, deltas and
ridges. It is the only part of the fingerprint which concerned during classification of the
fingerprints.
• The two innermost ridges which start parallel, diverge and surround or tend to surround the
pattern area are known as Type lines.
• The point on a ridge at or in front of and nearest the centre of the divergence of the type lines
is referred as the delta. And the core is the approximate centre of the fingerprint pattern.
• There are specific rules for core and delta, which govern their selection.
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CLASSIFICATION OF FINGERPRINTS
• More than fifty fingerprint classification systems are used in different countries.
• Various types of Classification of fingerprints are-
Tripartite System ( Francis Galton)
Ten digit classification systems
 Henry’s Classification System
 FBI-Henry’s Classification System
 Chatterjee Henry’s Classification System
 Vucetich Classification System( Argentine System)
 Purkinje’s Classification System
 NCIC classification system
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HENRY’S SYSTEM OF CLASSIFICATION
• It is mainly developed by Sir Edward Richard Henry in 1897.
• The percentage of occurrence of plane arch, tented arch and composite pattern are relatively low
as compared to whorl ad loop pattern.
• Thus for the purpose of primary classification system, plane and tented arch have been grouped
under loop pattern and composite pattern are grouped under whorl pattern.
• So the ATUR (Plane arch, tented arch, ulnar loop and radial loop) is considered as loop pattern
whereas WCSX(Whorl, Composite patter, double loop and Accidental pattern) are considered
under whorl pattern.
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PRIMARY CLASSIFICATION
• Fingers are paired into groups
• Starting from Right Thumb numbered from 1 to 10
• Value Assigned if only whorl is present
• First pair Assigned a value of 16
• Consecutive pairs assigned a value with division of 2
• Values are added
• Finally unit value is added to the final value
Fingers R T R I R M R R R L L T L I L M L R LL
Numbering 1 2 3 4 5 6 7 8 9 10
Value 16 16 8 8 4 4 2 2 1 1 16

• Even Numbered Fingers are placed at Numerator while Odd Numbered Fingers are placed at
Denominator.
• +1 will be added in both numerator and denominator.
• Formula for Primary Classification-
= Primary Classification
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Ex:
• If a whorl was found on the R. Index finger and the R. Middle finger, the following fractions
would result:
16 + 0 + 0 + 0 + 0
------ ------ ------ ------ ------
0 + 8 + 0 + 0 + 0
• If we add 1 to the top and bottom, we end up with a fraction of 17/9.
16 + 0 + 0 + 0 + 0 + 1 =17
------ ------ ------ ------ ------ ------ =17/9
0 + 8 + 0 + 0 + 0 + 1= 9
• Maximum Value will be 32/32 while Minimum would be 1/1.
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SECONDARY CLASSIFICATION
• Pattern on Index fingers are considered for this classification. Both Right Index & Left Index
are considered.
• It is given by Capital Letter Symbols for the pattern of both fingers. Right Index is placed as
Numerator & Left Index as Denominator.
• Nine basic patterns on Index fingers are given by-
Sr. No Pattern Symbol
1. Plain Arch A
2. Tented Arch T
3. Ulnar Loop U
4. Radial Loop R
5. Whorl W
Sr. No Pattern Symbol
6. Central Pocket Loop C
7. Lateral Pocket Loop
8. Twin Loop S
9. Accidental X
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SECONDARY CLASSIFICATION
• Formula for Secondary Classification-
Right Index
-----------------
Left Index
• For Ex- Right Index is having Whorl pattern & Left index is having Radial Loop then it is
written as
Secondary Classification = W/U
= Secondary Classification
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SUB-SECONDARY CLASSIFICATION
• This classification is applicable for Whorls & Loop patterns.
• It is to be represented by the Symbols of I (Inner), M (Meeting). O (Outer) types.
• In this classification, Index, Middle & Ring fingers of right hand are placed at numerator and
same fingers of left hand at denominator position.
• Symbols I,M & O are given on the basis of ridge tracing in the Whorl pattern.
• In case of Loop pattern, I,M & R are given.
• Formula for Sub Secondary Classification is
I M R (Right Hand)
I M R (Left Hand)
= Sub Sec Classification
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SUB-SECONDARY CLASSIFICATION
• For Index finger –
If the ridge count is :-
1 to 5, then I type
6 to 12, then M type
13 to above, then O type
• For Middle finger –
1 to 6, then I type
• For Ring finger –
1 to 7, then I type
• Example – If the right index, middle & ring fingers have ridge count of 4, 9, & 14 and for left
index, middle & ring fingers have ridge count of 8, 18, 3 respectively.
• Then it will be shown as SS. C = <I> <M> <R> Right Hand
<I> <M> <R> Left Hand
I M M
M O I
Sub Secondary Classification = 22

SINGLE DIGIT CLASSIFICATION ‘OR’
BATTLEY’S SINGLE DIGIT CLASSIFIACTION
• It is not necessary a print of all the ten fingers will be found on the scene of crime. In maximum
cases, chance prints left behind by criminals then it become very difficult to identify the
individual by a single fingerprint.
• So, Battley and Cherril developed the idea of single- fingerprint system that did not require the
all 10 known fingerprints of an individual.
• Several system of classifying single fingerprint has been devised but the one commonly used is
Battley’s system. Because it is found to be most accurate and practical methods of handling finger
prints.
• In this type of system, it requires the use of special magnifying lens provided with a retical.
• In the centre of retical a dot around which 7 circles are drawn with radii of 3,5,7,9,11,13 and
15mm respectively.
• A letter starting with centre called A and reading outward as B,C,D,E,F and G for the successive
circles.
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SINGLE DIGIT CLASSIFICATION ‘OR’
BATTLEY’S SINGLE DIGIT CLASSIFIACTION
• In interpreting pattern, the Battley’s system uses a special core which should coincide with core
of pattern to obtain delta cutting co-centre will result radii with the symbolized letter.
• The example can be if delta of a pattern is cutting 9mm radii circle which is represented with D,
then the answer will be 9D.
• The disadvantage of this system is that it cannot be used for those prints which have arch
pattern because of the absence of core and delta in the print.
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SEARCH OF FINGERPRINTS
• Locating visible or plastic prints at the crime scene normally presents little problem to the
investigator because these prints are usually distinct and visible to the eye. Locating latent or
invisible prints is much more difficult and requires the use of techniques that make the print
visible.
• Hard and nonporous surfaces (such as glass, mirror, tile, and painted wood) require different
development procedures than do surfaces that are soft and porous (such as paper, cardboard, and
cloth) and various places fingerprints impression found such as vehicles, bathrooms, utensils,
leftover objects, Documents, Dead bodies, etc.
• Prints on the former surfaces are developed preferably by the application of a powder or by
treatment with Super Glue, whereas prints on the latter generally require treatment with one or
more chemicals.
• Sometimes the most difficult aspect of fingerprints examination is the searching of prints.
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FINGERPRINT BUREAU
• The first fingerprint bureau in the world was established at Writer’s building at Calcutta in
1897 by the efforts of police chief of the South Bengal Sir Edward Richard Henry. Another
CFBP was established in Shimla in 1905.
CFPB (Central Finger Print Bureau)
• It was initially established in Calcutta in 1955 under the administration control of Intelligence
Bureau (IB). In 1973, the administration control was reassigned to CBI and in 1986 the CFPB
was finally under the administration control of NCRB (National Crime Record Bureau).
• The main function of CFPB is to maintain a database of fingerprint of criminal (national and
international) and dissemination the information. It also maintained the record of international
criminal sent by the international police organisation. In CFPB examination of questioned
fingerprint samples also takes place referred by Central Govt. Department and Govt. of India.
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FINGERPRINT BUREAU
SFPB (State Finger Print Bureau)
• The first state fingerprint Bureau was set up in Bengal. After that in every state one fingerprint
bureau and one single digit fingerprint bureau at district level has been established.
• Main function of these bureaus is to recording the fingerprint slip of the convicted person in that
particular state. Examination and comparison of fingerprints are being carried out for criminal
investigation.
• Main responsibility of Fingerprint expert is to develop the chance print left by the criminal at
the crime scene and matching the fingerprint with the existing criminal record. They also give
exert opinion in civil and criminal cases regarding fingerprint. Fingerprint bureau of each state
solves the cases and send their annual record to the CFPB.
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MODULE 2: CONTENTS
• Sweat and its Composition.
• Chance Fingerprints, Latent & Visible Fingerprints, Plastic Fingerprints.
• Methods of Developing Fingerprints
• Development of Latent Fingerprints.
• Conventional methods of development of fingerprints – fluorescent method, magnetic powder
method, fuming method, chemical method etc,
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SWEAT AND ITS COMPOSITION
• Sweat is deposited on every surface touched by hands and adhere to it. Thus the study of
components of sweat is useful for the development or visualization of latent fingerprint (not
visible to naked eyes).
• The dermis layer of skin contains three major secretory glands which are responsible for the
secretion of sweat, these glands are -
 Eccrine Gland
 Apocrine Gland
 Sebaceous Gland
• Out of that three, eccrine glands are present throughout the human body surface and only that
are responsible for the sweat secretions over palm and sole areas of the body.
• Gland formation begins on the palms and soles at around 3 months EGA as well as on other
body surface by 5 months EGA. Typically, the glands are fully matured by the 8th month of fetal
development. 29

• The eccrine sweat contains excess of 98% water with numerous organic and inorganic
constituents. The primary component of sweat is water and it also contain 0.5-8 mM ammonia,
which is 20-50 times higher than plasma levels.
• The sweat contains trace amounts of inorganic substances like- magnesium, fluoride, bromide,
chloride, iodide, iron, zinc, copper, cobalt, zinc, manganese, molybdenum, sulphur, tin, mercury,
phosphate and sulphate. Sodium, potassium, calcium, chloride and bicarbonate are also the
components of sweat.
• The sweat includes organic components like various amino acids, proteins and lipids. Serine,
glycine and alanine are the most abundantly found amino acids in the sweat.
• The protein content of secretion contains albumins, globulins, lipoproteins, and several
glycoproteins. Lactate and urea are present at significant levels in perspiration.
• Other miscellaneous components of sweat include creatine, creatinine, glucose, pyruvate, cAMP
and immunoglobulins.
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• Enzymes such as phosphatase, acid phosphatase, acetyl cholinesterase, isocitric and succinic
dehydrogenases are included in sweat composition.
• Lipid components such as fatty acids, sterols are also found in the eccrine sweat. Various
drugs, vitamins, ethanol and other volatile organic compounds also has been detected in
sweat.
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LATENT, PATENT & PLASTIC FINGERPRINTS
• LATENT PRINTS - Chance impressions, or what is more commonly known as latent fingerprints
are fingerprint impressions secreted in a surface or an object and are usually invisible to the
naked eye.
• These prints are the result of perspiration which is derived from sweat pores found in the ridges
of fingers.
• When fingers touch other body parts, moisture, oil and grease adhere to the ridges so that when
the fingers touch an object, such as a lamp, a film of these substances may be transferred to that
object. The impression left on the object leaves a distinct outline of the ridges of that finger.
• These fingerprints must be enhanced upon collection and, because they serve as a means of
identifying the source of the print, they have proven to be extremely valuable over the years in
the identification of its source.
32

LATENT, PATENT & PLASTIC FINGERPRINTS
• PATENT PRINTS - are visible prints that occur when a foreign substance on the skin of a finger comes in
contact with the smooth surface of another object.
• These prints leave a distinct ridge impression that is visible with the naked eye without technological
enhancement of any kind.
• The tried and true "blood on his hands" evidence is an example of patent prints recovered from a crime
scene or scene of interest to investigators.
• These foreign substances contain dust particles which adhere to the ridges of the fingers and are easily
identifiable when left on an object.
• PLASTIC PRINTS - are visible, impressed prints that occur when a finger touches a soft, malleable surface
resulting in an indentation.
• Some surfaces that may contain this type of fingerprint are those that are freshly painted or coated, or
those that contain wax, gum, blood or any other substance that will soften when hand held and then retain
the finger ridge impressions.
• These prints require no enhancement in order to be viewed, because they are impressed onto an object and
are easily observable.
33

METHODS OF DEVELOPING FINGERPRINTS
• There are various methods of developing fingerprints.
Fingerprint Powders
Iodine Fuming techniques
Ninhydrin Method
Cyanoacrylate Fuming/ Super Glue
Physical Developer techniques
Vacuum Metal Deposition
Silver Nitrate
ALS (Alternating Light Source)
DFO (1,8-Diazafluoren-9-one) method
34

FINGERPRINT POWDERS
• Powder are excellent medium to develop latent print on small surface in compound hands they fail only
in case of old print and printed on rough surface.
• The Powder of an shades and varieties have been used; however the following powder meet most of the
situation in fingerprint development
• The grey powder is used for all dark colored surface or black surface
• The black powder is use against light black background
• The fluorescent (anthracene) powder is used for multi- colored surface. fingerprint developed by
anthracene are exposed to ultraviolet rays and photograph. The Prints develop with fluorescents powder
need reversal that is the point are prepared from the transparencies.
• Metallic powder ( aluminum, copper, brass, gold, anti money) and universal powder are also used in
special situation the metallic or Universal powder are useful for fingerprints on sticky surfaces.
• The use of magnetic powder with Magna brush facilities developing fingerprint on Grey area the Powder
used should be amorphous dry and uniform consultancy of floor it should be stable somewhat streaky and
chemical non reactive inert
35

FINGERPRINT POWDERS
• Magnetic Brush and Powder.
• To increase the efficiency in development of latent print investigation officers also use magnetic brush
and powder. The magnetic brush work with magnetic powder only which are available in many color grey,
black, red, yellow, silver.
• The brush used is a magnetic rod which is used in or out of a small cylinder and thus is created a
magnetic field which cause the metal powder to appear as a brush allow the operator to process the
crimes in area.
• This brush can be used in location latent fingerprint on paper, tissue, light wood, leather, cardboard, box,
plastic and others .
• Material Powder are the most basic and easiest forms of lifting latent prints. Magnetic powder cannot be
used on metal surface.
• Black powder are used on a large range of surfaces while Fluorescent powder are used on dark surface.
36

FINGERPRINT POWDERS
Magna Brush and Magna powder (left)
and developed latent print ( right)
Latent print before and after powder
dusting
37

BY FINGERPRINT POWDERS
White powder works especially well on glass, chromed metals, plastic bags and
dark colored surfaces. White powder generally consists of Titanium Oxide powder
and an earth powder for base. The Titanium adheres well to the oils of the print
and provides an excellent contrast to most surfaces it is used on, whether it is
conventional or magnetic, or used on porous or non-porous surfaces.
Silver/Gray (aluminum) powder performs best on glass, plastic and rubber. The
aluminum component of the powder adheres to prints on non-traditional surfaces and
provides good contrast to the background surface.
Bi-Chromatic powders are typically a combination of black and aluminum powders,
and were created to adapt to colored surfaces. When processing with Bi-Chromatic
powder, any latent prints developed will be seen as black ridges on the light parts
of the surface and light ridges on the dark part of the surface. Once these prints are
lifted onto a white backing card, they will always appear as dark ridges.
38

BY FINGERPRINT POWDERS
Black powder is manufactured from a variety of carbon-based powders with a
binder or earth powder added for stability. This staple of fingerprint powders
readily adheres to the oily residues from the fingers and other body parts and is the
most versatile of the fingerprint powders in that it can be applied to many surface
types: porous and non-porous alike.
Fluorescent fingerprint powders are designed to develop latent fingerprints on
multi colored surfaces. The powders have fluorescent properties and may offer
a better contrast to the background than conventional powders.
Magnetic powder is used on non-magnetic surfaces, and regular powder on
iron-based surfaces. However, regular fingerprint powder is inappropriate for
some surfaces, including many plastics and textured surfaces, where magnetic
powder develops latent prints very well.
39

CHEMICAL METHOD OF LATENT FINGERPRINT
• The use of chemical reagent is done because it reacts with the organic and inorganic compound
found in the Sweat excretion constituents. It is one of the simple and effective means of
developing latent print.
• Chemical method of developing latent fingerprint usually makes use of the presence of the
chlorides in the latent image by exploring the paper or other such objective to the action of same
chemical which react with the chloride to provide visual print.
• Commonly used methods are
Iodine Fuming method
Silver Nitrate method
Ninhydrin method
Cyanoacrylate Fuming method
DFO (1,8-Diazafluoren-9-one) method
40

Iodine Fuming method
The iodine fuming technique can be used on both porous and non-porous surfaces. It works best
on fresh prints (usually no more than a few days old).
Iodine fumes are toxic and also strongly corrosive.
Since the iodine fuming technique is in principle non-destructive, other techniques can be used
afterwards (e.g., the ninhydrin treatment of paper).
In developing latent prints with iodine, a long-used method, iodine crystals give off vapors
(sublimation) that adsorb physically to the oily substances of a fingerprint.
The brown-colored prints that are developed with iodine are not permanent unless fixed.
Benzoflavone fixes and also darkens the print.
41

Silver Nitrate method
• Silver nitrate development is based on the reaction of soluble silver nitrate with the sodium
chloride (salt) that is present in most latent fingerprints to form insoluble and light-sensitive
silver chloride.
• Exposing the silver chloride produced by this reaction to sunlight or an ultraviolet lamp causes
the silver chloride to be reduced to metallic silver, making the latent prints visible as black or
dark gray traces. Because sodium chloride is not volatile, even very old latent fingerprints retain
it and can be developed by silver nitrate.
• Silver nitrate development is destructive (as is Physical Developer), so if it is to be used it must
be used after all other methods have been attempted.
• Iodine fuming, ninhydrin, and most other development methods don’t interfere with silver
nitrate, so forensics labs often use silver nitrate development as the final step, in the hope of
revealing latent prints that were not revealed by the other methods.
42

Ninhydrin method
• It is the most common method in developing latent fingerprints.
• Ninhydrin is a chemical powder that is soluble in ethanol or acetone at room temperature. When
a solution of ninhydrin is applied to fingerprints (usually via a simple spray bottle).
• The ninhydrin reacts with the amino acids that are present in fingerprint residue. The reaction
causes the production of an intense purple dye called “Ruhemann’s purple”.
• The treatment generally involves dipping the items in a ninhydrin solution and then leaving the
prints to develop over 24 to 48 hours. Prints more that 50 years of age have been developed by
this process.
• Fingermarks treated with ninhydrin can be further enhanced by treatment with a zinc or
cadmium salt solution. The coordination complex that is formed results in a color change and
gives a print that is luminescent under certain conditions. At low temperature and with
appropriate excitation from a high-intensity light source considerable fingerprint enhancement
can be achieved.
43

DFO (1,8-Diazafluoren-9-one) method
• The chemical reagent 1,8-diaza-9-fluorenone, commonly known as DFO, became available as a
more sensitive technique for fingerprint detection on paper. DFO reacts with amino acids in the
latent fingermark in much the same manner as for ninhydrin.
• However, heat is required for successful development and the reaction product is much paler in
color than that achieved with ninhydrin.
• The advantage of DFO is that developed prints are highly luminescent at room temperature
without any additional treatment. Studies have shown that up to three times the number of
fingerprints can be developed with DFO in comparison with ninhydrin. DFO can be used before
but not after ninhydrin processing.
• The disadvantages of DFO include the requirement for a specialized light source, the relative
high cost of the reagent, and the unsuitability of the technique for luminescent substrates.44

Cyanoacrylate Fuming method
• The super glue or cyanoacrylate method is a forensic science technique that uses the vapors of
super glue to develop latent fingerprints.
• The fuming is performed in a developing chamber using super glue and water which allows the
vapors to adhere to the fingerprint, making the fingerprint visible.
• Once the print is visible, you can enhance it by using dyes or powders.
• Super glue fuming is a way to make a fingerprint semi-permanent so the print can be dusted
(lightly brushing fine powder onto the residue left by a fingerprint) and tape-lifted (use tape to
put over the developed fingerprint and lift the print and place onto a fingerprint card) various
times and not be disturbed or ruined.
45

Super Glue Fuming. Iodine Fuming Method Silver Nitrate Method
Ninhydrin Method
DFO (1,8-Diazafluoren-9-one) Method
46

VACUUM METAL DEPOSITION
• Vacuum Metal Deposition (VMD) is the most powerful technique for developing latent
fingermarks on non-porous or semi-porous exhibits.
• VMD is faster and develops more fingermarks than standard and traditional methods, with fine
detail and high definition.
• VMD is the optimal technique for a wide range of non-porous and semi porous exhibits, including
flexible plastic packaging, plastic bottles, glass, fabrics, firearms, glossy paper, waxed paper,
paper bank notes, polymer bank notes, wood etc.
• This technique can generate an improvement of latent fingerprint development of up to 15%
when compared to traditional methods.
47

ALS (ALTERNATING LIGHT SOURCE)
• Alternate light sources provide light at different wavelengths that may or may not be visible to
the naked eye. When used in combination with the proper filter, these various wavelengths of
light can help visually identify different types of latent prints.
• The use of fluorescent enhancement processes that compliment a light source greatly increases
the types of surfaces from which a latent fingerprint can be detected.
• Consider the difficulties of dusting and lifting a print off of the following surfaces: thin plastic
bags, rigid duct tape, thin aluminum foil, heavily grained wood, concrete wall, brick, printed
glossy magazine pages, paper products, etc.
• Using traditional methods, fingerprint evidence on these and other types of surfaces may go
undetected or even dismissed because they could not be detected with enough detail. Alternative
Light Source techniques have been successfully utilized for revealing latent prints on these and
many other types of textured surfaces, backgrounds which mask ridge detail, fragile surfaces,
and contaminated surfaces.
48

ALS & VACUUM METAL DEPOSITION
ALS (Alternating Light Source) Vacuum Metal Deposition VMD
49

MODULE 3: CONTENTS
• Digital Imaging and Enhancement of Fingerprints
• Application of Laser and Other Radiations to develop Latent Fingerprints
• Development of Latent Prints on Skin.
• Poroscopy and its Significance.
50

DIGITAL IMAGING AND ENHANCEMENT OF
FINGERPRINTS
• After the latent has been developed, they need various enhancements techniques so that the
ridges can be clearly studied.
• Alternative light sources (other than room light) could be used for the enhancement and
visualization of latent fingerprints. High-intensity lamps, UV light sources, lasers, and xenon arc
lamps have been utilized in the development of latent prints and have produced better latent
print images than regular room light.
• Image enhancement of fingerprints is done so that the image becomes clearer for the
supplementary operations.
• Also, the images of fingerprints acquired from scanner or any other media are not assured with
perfect quality, those enhancement methods, for increasing the contrast between ridges and
valleys and for connecting the false broken points of ridges due to insufficient amount of ink, are
very useful for keep a higher accuracy to fingerprint recognition. 51

DIGITAL IMAGING AND ENHANCEMENT
OF FINGERPRINTS
• For photographic purposes, there are two important types of digital images—color and black and
white. In case of colored images, color pixels are found whereas black and white images are
formed from pixels having various shades of grey.
• The image enhancement technique involves two steps, firstly the histogram equalization and
secondly, the Fourier Transformation.
• Fingerprint Image Enhancement by MATLAB - The power that MATLAB brings to digital image
processing is an extensive set of functions for processing multidimensional arrays of which
images (two-dimensional numerical arrays) are a special case.
• It is has various features which are capable of the MATLAB numeric computing environment.
• The expressiveness and the functions pertaining to the MATLAB language makes the operations
required for image processing easy to be written in a clear and compact form thereby acting as a
best software prototyping environment. 52

APPLICATION OF LASER AND OTHER RADIATIONS TO
DEVELOP LATENT FINGERPRINTS
• Laser detection of latent fingerprints is an extremely sensitive technique with a wide range of
applicability. `The methodology is based on the principle that a luminescent fingerprint, impinged
on a non-luminescent surface, produces laser-excited fluorescence.
• The fluorescence so produced provides intrinsically such high sensitivity that fingerprints may be
detected on difficult and unusual surfaces. The method also ensures detection of weak, as well as
old latent fingerprints. Laser technique is often used as a supplement to conventional procedures
of fingerprint detection.
• Application of Lasers to Fingerprint Detection - The most common device used for the detection
of latent fingerprints on difficult surfaces is the argon laser (Ar-laser).
• The surface impinged with the fingermark is illuminated with the blue green beam from the Ar-
laser.
53

APPLICATION OF LASER AND OTHER RADIATIONS TO
DEVELOP LATENT FINGERPRINTS
• The strong fluorescence produced in a post-treated fingermark with an Ar-laser enables detection
of imprints on unusual surfaces. It also enables detection of very old fingerprints. The prints may
be processed at room temperature.
• An arc lamp too produces fluorescence but only when the sample is plunged into liquid nitrogen
and illuminated at 200ºC. Thus larger articles cannot be examined by the arc lamp method .
• The size and shape of the exhibit does not matter when illumination has to be carried out by a
laser. There are a few disadvantages associated with laser.
• The casework has to be performed at the fingerprint bureau. v Portable lasers, which may be
carried to the scene of crime, are not yet available.
• Laser equipment is quite costly. When optical spectroscopic techniques are used in combination
with lasers, the operational procedures become tedious and complex. However, the end results
obtained with lasers are so remarkable that one becomes inclined to believe that their merits
outweigh the demerits.
54

DEVELOPMENT OF LATENT PRINTS ON SKIN
• Skin is the most critical substrate for the recovery of fingerprints, due to constant renewal,
regeneration and elasticity of the skin and also due to regulation of body temperature,
perspiration removes latent prints, environmental factors etc.
• Powder method is basic and least complicated method but not useful on wet latent fingerprint. In
most of the cases, the Cyanoacrylate fuming method is used and is recommended method that
develops clear, stable, white colored fingerprints but other methods like Ruthenium tetroxide –
RTX can be used effectively, which are efficient and non-destructive.
• Magnetic powder can be explored to recover any possible latent prints on the victim’s skin.
However, most of these methods suffer from the recovery time constrains and are influenced by
factors like decomposition, environment and circumstantial conditions and longevity of latent
prints on skin
55

DEVELOPMENT OF LATENT PRINTS ON SKIN
• The comparative studies for these methods have been given below
56

POROSCOPY AND ITS SIGNIFICANCE
• Poroscopy is a method of personal identification through the comparison of the impressions of
sweat pores (present on friction ridges of palmar and plantar surfaces). The method was
discovered and developed by Edmond Locard in 1912.
• Immutable and Persistent throughout lifetime.
• Size of pores may vary between Childhood, Adolescence and Old Age.
• Shape varies from
Round
Elliptical
Oval
Square
Rhomboid
Triangular
Magnified image of ridges showing
various sizes of pores.
57

POROSCOPY AND ITS SIGNIFICANCE
• Poroscopy is also used as a valuable tool in anthropological studies in forensic science and
considered as an essential component in the modern automated fingerprint recognition system.
• Poroscopy is the third level detail of the friction ridges and therefore, felt more accurate and
reliable.
• Several studies have been conducted on palm prints of individuals and sweat pores for their
shape, size, position, interspacing, and number per unit area.
• Findings showed that the identification of an individual with the help of poroscopy was as
reliable and accurate as ridge characteristics and can be compared with the results obtained
through the study of ridge characteristics
58

MODULE 4: CONTENTS
• Taking of finger prints from living and dead persons.
• Preserving and lifting of fingerprints.
• Photography of fingerprints.
• Digital transmission.
• Comparison of fingerprints, basis of comparison, class characteristics, individual
characteristics, various types of ridge characteristics, etc.
• Automatic Fingerprint Identification System
59

PRESERVATION OF FINGERPRINTS
• Once a fingerprint is developed by using various techniques according to the surface. The next
thing is to preserve this develop to print.
• Prints developed on movable articles are preserved and transported to lab as it is. Print on non-
movable articles are the first photograph with a rolled scale.
• One of the traditional method of preserving prints is while lifting then careful with the help of
fingerprint lifting card and fingerprint evidence preserved by the various paper bag, air tight
plastic bag etc.
• Fingerprints which are fresh enough to Steel contain water can also be preserved with super
glue. The liquid is made of many molecules of ethyl cyanoacrylate which when exposed to air the
moisture in air will cause it to polymerise.
• Thus on exposing it to fingerprints it will polymerize on ridges of print forming a hard surface
and thus preserving it. 60

COMPARISON OF FINGERPRINTS
• Comparison is the observation that two impression have ridge characteristics similar shapes
which occupy the same relative position in both pattern.
• When lift is made ,the latent print examiner must conduct a comparison, where appropriate.
• For the comparison of two fingerprints it is essential that the basis pattern is same. If the basic
pattern is different then there is no need for identification of ridge characteristics. The
impression are undoubtedly from different person but in case the basic pattern are same then
the core and delta has to be located and examination of ridge characteristics around the core
and delta has to be studied.
• If the ridge characteristics are found in the same order with their relative position then it can
be safely stated that both the impressions belong to the same individual
61

BASIS OF COMPARISON FOR FINGERPRINTS
Pattern area- The pattern area is only part of fingerprint impression which is
used in interpretation as well as classification of print. The part of loop and
whorl pattern in which core, delta and ridges are appeared. The pattern area in
loop and whorl are enclosed by type lines. It is absent in arch pattern because
of the absence of core, delta and type lines.
• Type lines- Two innermost ridges which starting run parallel to each
other and then diverse and tend to surround the pattern area.
Core & Delta- Core is the approximate centre of the finger
impression. A triangular ridge pattern from which ridges go in
different directions above or below a triangle. It is present in front
of or nearest of the divergence of the type lines.
62

CLASS CHARACTERISTICS
• Fingerprint examiners use the general or class characteristics for the initial comparison and
include or exclude an examined fingerprint from the further analysis.
• The general characteristics include pattern types (arch, loop, or whorl pattern) of the
fingerprint.
• All fingerprints fall into one of the three basic pattern types :
1. Arch patterns: Accounts for approximately 5-15% of pattern types.
2. Loop patterns: Accounts for 60-65% of pattern types.
3. Whorl patterns: Accounts for 30-35% of pattern types.
Arch patterns:
A. Plain arch
B. Tented arch
Loop patterns:
A. Ulnar Loop
B. Radial Loop
Whorl patterns:
a. Plain
b. Double loop/lateral loops
c. Central pocket loop
d. Accidental
63

INDIVIDUAL CHARACTERISTICS
• Individual characteristics include ridge characteristics also known as "Galton details"
(minutiae) present in the particular pattern type.
• If the general pattern type appears to match, then the examiner focuses on the individual
characteristics.
• The palmer surface of hand and planter surface of the feet contains unique and discontinuous
ridges. These ridges are also termed as minutiae.
• These friction ridges contain various features which are present in sufficient in number in every
individual.
• A single fingerprint may contains more than 80 ridge characteristics.
64

RIDGE CHARACTERISTICS
Ridge characteristics or Galton details are described in the following forms:
1. Ridge ending- Point where ridge suddenly ends.
2. Dot- Small point like structure.
3. Short ridge- Ridge that flow for short distance and ends.
4. Bifurcation- Single ridge divides into two branches.
5. Trifurcation- Single ridge divides into three branches.
6. Enclosure or eye- Single ridge splits for a short distance and again connects to be a single ridge, by
forming an empty space.
7. Lake- Prolonged enclosure.
8. Hook or spur- A notch protruding from a ridge.
9. Bridge or Interjunction or Cross over- Two adjacent flowing ridges are connected by the small ridges.
10. Intersection or Ridge crossing- Two or more parallel flowing ridges intersects each other.
65

AUTOMATIC FINGERPRINT
IDENTIFICATION SYSTEM
• The Automatic Fingerprint Identification System (AFIS) is a biometric identification
methodology that used digital imaging technology to obtain, store and analyse fingerprint data.
• It has necessary hardware and software to acquire, process, store ,digitize and retrieve
fingerprint from ten print cards.
• The AFIS compares these prints and identifies possible matches based on minutiae data.
• This processing of the prints are for the purpose of establishing identification and creating an
individuals criminal history. This system serves as the central repository for identification
records relating to person arrested throughout the country.
• The AFIS was originally used by the U.S Federal Bureau of Investigation (FBI) in criminal
cases.
• It has gained favour for general identification and fraud prevention. 66

REFERENCES
• Hawthorne, M. R. (2009). Fingerprints: analysis and understanding. Boca Raton: CRC Press.
• Wertheim, Kasey (2011). Fingerprint Sourcebook- Chapter 3: Embryology, and Morphology of
Friction Ridge Skin, US Department of Justice Office of Justice Programs United States of
America.
• Champod, C., Lennard, C., Margot, P., Stoilovic, M. (2016). Fingerprints and Other Ridge Skin
Impressions (Second ed.). CRC Press.
• Lee, H. C., & Gaensslen, R. E. (2001). Advances in Fingerprint Technology (Second ed.). CRC
Press.
• Kucken, M., & Newell, A. C. (2004). Fingerprint formation. Journal of Theoretical Biology,
235(1), 71-83. doi: 10.1016/j.jtbi.2004.12.020.
• "SCIENCE." Crime Scene Investigator Network. Available at: https://www.crime-scene-
investigator.net/fbiscienceoffingerprints.html#chapter_ii (Accessed: 25 April 2020)
• "National Forensic Science Technology Centre" (2013). A Simplified Guide to Crime Scene
Investigation. Available at: http://www.forensicsciencesimplified.org/prints/principles.html
(Accessed: 24 April 2020)
67

• http://ncrb.gov.in/central-finger-print-bureau
• Bindra. B, Jasuja. O. p, and Singla. A. K (2000) “Poroscopy: A method of personal identification
revisited”
• “Forensic Science in Crime investigation”, by B. S. Nabar (2001)
• “Fingerprints Analysis and Understanding
• R. K Tiwari, K V Ravikumar, Development of Forensic India ,A Historical Account Journal of the
Indian Academy of Forensic science 1999.
• B.S Nabar, Forensic Science in Crime Investigation , Asia law house 2011.
• https://www.interpol.int/en/How-we-work/Forensics/Fingerprints.
• Dr. B. R Sharma : Forensic science in Criminal Investigation & Trials, Fifth Edition , Reprint
2017 ISBN 978-93-8651-560-5. Page no -305 to 324.
• G.S Sodhi Thomas GL, 1978, The physics of fingerprint and the latent detection, Egyptian
Journal of forensic science, XXX,11-31.
REFERENCES
68

• G.S Sodhi, Knowles AM,1978, Aspect of physicochemical method for the detection of fingerprint,
Egyptian Journal of forensic science,XXX,13-21.
• G.S Sodhi, Kuno Y,1956, Human Perspiration, Egyptian Journal of forensic science, XXX,
• G.S Sodhi, Scrutun, B, Robins BW 1975, The deposition of fingerprint, Egyptian Journal of
forensic science, XXX,8-23.
• H. James Stuart and Jon J. Nord by 2009, Third edition Forensic science, An introduction of
scientific and investigation Techniques, 360.
• Dr. Sharma. B.R: Forensic science in Criminal Investigation &Trails, Forth Edition, Reprint
2017 ISBN 978-8651-5.Page no 315-321.
• Meuwly, D. Forensic 2006 Individualization from biometric data. Science Justices 46(4) 315-321
• A. Andre. Moenssens and B. Stephan Meagher 2004 Federal Rules of Criminal Procedure. The
Committee on the Judiciary, House of Representatives; 4-5.
REFERENCES
69

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70

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