Fingerprints History
• Earliest recognition of uniqueness of
fingerprints & their suitability for personal
identification apparently came from the
ancient Chinese.
• They used a thumbprint in lieu of a
signature on legal conveyances & even
criminal confessions. This was due to the
prevalence of illiteracy making
fingerprinting a practical measure.
Fingerprints
• First scientific recognition of fingerprints:
from certain late 17th century writings.
• 1684 Dr Nehemiah Grew report described
ridges & pores on hands & feet. This
started it all.
• Johannes E. Purkinje – first person to
devise a system of classifying fingerprints.
Fingerprints
• He published thesis in 1823 describing 9
fingerprint patterns, gave each a name &
set down rules for individual identification,
many of which are still followed today.
• Two men recognized use for identifying
people from fingerprints (Japan & India)
working at same time but not aware of
each other’s work.
Fingerprints
• 1877 – William Herschel sought to
implement his fingerprint system in Bengal
jails but couldn’t get permission.
• Dr. Henry Faulds, Scottish physician &
surgeon discovered that oil & sweat from
pores resulted in latent (invisible) prints
that could be developed with powders. He
used this technique to exonerate a man
accused of burglary using fingerprints
Fingerprints
• Faulds & Herschel argued over who was
first in pioneering fingerprinting. Faulds
was referred by Charles Darwin to Sir
Francis Galton to settle argument.
• Galton was interested in who pioneered it.
He wanted to join in the new field.
Fingerprints
• Galton published textbook, Finger Prints,
in 1892 giving credit to Herschel as “the
first to devise a system for the use of
fingerprints for identification” & most
important, setting forth a practical method
of classification - Not just by patterns but
by entire set of fingerprints of an individual
so they could be filed.
Fingerprints
• Edward Henry, Herschel’s successor in
India, became interested in fingerprinting
& he began work on his own classification
system.
• He simplified where possible, and added
complexity where needed. Overall, he
shaped the whole into a fully practical &
workable system.
Fingerprints
• Completed in 1899, his system was
published in book form the following year.
• In 1901, the Henry system of fingerprint
classification & filing was implemented in
England & Wales.
• With later modifications by the FBI, the
Henry system continues in use to the
present day.
Fingerprints
• 1894 Britain: primary identification method:
bertillonage (system of anthropometry
created by Alphonse Bertillon involving
recording 11 measurements.
• By turn of century, Scotland yard began to
rely on fingerprints. Reluctantly, Bertillon
added space on his record cards but for
the right hand only.
Fingerprints
• 1903, in the U.S. came case that marked
the beginning of the end of bertillonage.
• 5-1-1903: Will West sent to Leavenworth
Penitentiary. Bertillon measurements
taken. Clerk said he looked familiar, found
another card with similar measurements &
photo looking like him. Name on card was
“William West”. So both men were brought
together in same room.
Fingerprints
• Will & William West denied being related
but were actually identical twins. They had
similar fingerprint patterns, ear patterns &
wrote to the same brother, 5 sisters &
Uncle George.
• Fingerprints were taken & one man could
be distinguished from another without fail.
• The next day, the Henry method was
adopted by the prison.
Fingerprints
• In 1924, U.S. Congress established at the
then-Bureau of Investigation (now FBI) the
Identification Division to serve as nation’s
repository of all fingerprints records.
• During gangster era (20’s-30’s) fingerprinting captured imagination of American
public when it was seen as the premier
scientific weapon for dealing with public
enemies.
Fingerprints
• Public Enemy #1, John Dillinger, sought to
have fingerprints altered at same time he
had plastic surgery to alter his face.
• Result was a portion of each print scarred,
but more than enough was left to match to
his file prints. Scar patterns call attention
to themselves. Like everything in nature,
no two scar patterns are exactly alike.
Fingerprints
• Today FBI’s Identification Division is
largest unit with over 2,600 employees.
• More than 200 million sets of prints
represent more than 68 million individuals
on file in the Criminal Justice Information
Services Division.
• Non-criminal fingerprint files are kept
elsewhere.
Classification of Fingerprints
• Second reason to leave Bertillon method:
theft of Mona Lisa from the Louvre on
August 21, 1911.
• Thief left clear thumbprint on glass from
painting. Bertillon had no method of
classification for fingerprints on his cards.
• Two years later, thief arrested, print from
left thumb, prints on file from right hand.
Classification of Fingerprints
• Sir Edward Henry lived to see his system
of fingerprint classification become
adopted & succeed.
• With some modification, the Henry system
is the one we use today!
• The system divides fingerprints into 3
basic pattern types: arches, loops, &
whorls.
Classification of Fingerprints
• A fourth type listed in some books –
composites, also known as “accidentals” –
is considered a subtype of whorls: the
accidental whorl.
• These three main types are subdivided
into eight distinct patterns.
Classification of Fingerprints
• Arch: Plain or Tented
• Loop: Radial or Ulnar
• Whorl: Plain, Central Pocket Loop, Double
Loop, Accidental
• All human fingerprints have friction ridges
and these ridges form the basis of all
fingerprint patterns.
Classification of Fingerprints
• Arch Patterns:
– Plain Arch: ridges flow from one side of the
pattern to the other with a rise or wave in the
center; has a smooth rise & a gentle upward
curve; simplest of all fingerprint patterns;
generally gives no difficulty being correctly
identified.
Classification of Fingerprints
Classification of Fingerprints
• Arch Patterns:
– Tented Arch: More complex; has either a
central upthrust or well-defined angle;
regarded as transitional pattern between arch
& loop; example may be seen with “recurving”
ridge or other feature common to loop pattern.
But, it doesn’t have all 4 of pattern requisites
• Arches represent only about 5% of all
pattern types.
Classification of Fingerprints
• Loop Patterns: a loop has one or more ridges
that enter on one side, recurve, & flow back out
on same side.
• True loop-4 characteristics: core, approx. center
of pattern; delta or triangular area caused by
divergence of ridges; at least 1 recurving ridge
passing between core & delta; at least 1 ridge
count (# of ridges that cross or touch imaginary
line between precise core & precise delta).
Classification of Fingerprints
Classification of Fingerprints
• Radial Loop & Ulnar Loop: based on ridge
flow direction relative to 2 long bones on
forearm. Radius–thumb side; Ulna–little
finger side. To characterize fingerprint as
radial or ulnar loop, you must know which
hand it came from. Ridge flows are
reversed for left & right hands.
• Loops: 60% of all fingerprints; most
common fingerprint pattern
Classification of Fingerprints
• Whorl patterns:
– Plain whorl: has 2 deltas & at least 1 ridge
that makes a complete circuit about the core.
Some have concentric circles, ovals, or spiral
– Central pocket loop whorl: complex pattern,
perhaps most troublesome to classify;
essentially a combination of loop & whorl; has
all characteristics of loop with addition of
second delta near core & whorl-type ridge or
ridges circuiting around the core.
Classification of Fingerprints
Classification of Fingerprints
• How to differentiate between plain whorl &
central pocket loop whorl: Draw a line
between deltas: plain whorl must cross at
least 1 whorl-type ridge; in central pocket
loop whorl, this cannot happen.
• Double loop whorl consists of 2 separate
loop formation, each with its own core & 2
deltas.
Classification of Fingerprints
Classification of Fingerprints
• Accidental whorl is a pattern with 2 or
more deltas that may not be placed by
definition in any of the other classes.
• Whorls represent 35% of all fingerprint
patterns.
• Fingerprints intended for classification &
filing are recorded on standard 8” x 8”
cards.
Classification of Fingerprints
• These cards have spaces for rolled
impressions from each finger (inked &
rolled from one side to the other to record
the entire pattern) plus spaces for plain
impressions (four fingers of each hand are
pressed simultaneously, followed by the
unrolled thumb print) which serve as
checks on the rolled impression so they
are recorded in correct sequence.
Classification of Fingerprints
• Top of card, fingerprint classification &
name are recorded. On reverse, portrait
parle (“word picture”) of the subject:
height, weight, eye color, hair color, scars,
etc. & a place for full-face & profile photos.
Space for a “criminal history” is usually
included on cards recording fingerprints of
felons.
Classification of Fingerprints
• After prints are recorded & information put
on card, 1st stage of classification begins
called blocking out the set of prints by
placing in space below each rolled
impression a letter/symbol corresponding
to its pattern type.
• All whorls are marked W & ulnar loops are
signified by \ for right hand & / for left hand
Classification of Fingerprints
• For index fingers: A for plain arch, T for
tented arch, R for radial loop.
• For all other fingers the same symbols are
used but in lowercase a, t, & r.
• Next ridge counts of all loop patterns are
written in upper right corners of blocks.
Classification of Fingerprints
• Finally, each whorl-type pattern is given a
ridge trace from lower left side of left delta
to right delta dropping to a lower ridge
anytime the ridge ends or forks. If trace
ends within 1 or 2 ridges of right delta, a
meeting whorl is indicated, otherwise it is
designated as inner whorl or outer whorl
depending on whether trace ridge passes
inside or outside the right delta.
Classification of Fingerprints
• The symbol for appropriate ridge tracing –
I, M, or O – is written in upper right-hand
corner of each finger block containing a
whorl-type pattern to complete blockingout process.
• Formula for classifying fingerprints may be
composed of 7 possible divisions: primary,
secondary, subsecondary, major divisions,
second subsecondary, final & key.
Classification of Fingerprints
• Positions in completed classification line
are as shown below: Right hand on top of
line, left hand below the line
Key
Major
Divisions
Primary
Classification
Second
Subsecondary
Classification
Secondary
Subsecondary
Classification Classification
Final
Classification of Fingerprints
• Note some elements extend above &
below the line. Second subsecondary
classification, as its position indicates, is
optional, used when a group of fingerprints
becomes so large that it needs further
subdivision.
• Key is the ridge count of the first loop. For
the major divisions, ridge counts of thumb
are used.
Classification of Fingerprints
• Anything over 22 ridges is termed large.
• Primary classification, whorls are recorded
• Secondary classification represents the
patterns of index fingers.
• Subsecondary classification is based on
the 3 middle fingers of each hands with
whorls being designated I, M, or O & loops
depending on small or large ridge counts
being represented as I or O.
Classification of Fingerprints
• Final classification records ridge count of
the right little finger with provisions for that
print being a pattern other than a loop.
• Such as classification system permits
fingerprints to be filed & subsequently
retrieved.
• Primary classification alone permits
fingerprint cards to be divided into 1,024
groups.
Classification of Fingerprints
• Classification of “Scarface” Al Capone
29
L
L
1
1
U
U
IOI
IOI
Remember right hand on top of line & left
hand on bottom of line
6
Classification of Fingerprints
• Key for right thumb is 29, over 22 ridges
so Capone gets L/L, devoid of any whorltype patterns so assigned a simple 1/1 for
primary classification, index fingers ulnar
loops so U/U for secondary classification,
IOI/IOI for three middle fingers as subsecondary classification, ridge count on
right little finger is 6 for final classification.
Second subsecondary classification
omitted
Classification of Fingerprints
• In 1933, the FBI addressed the longtime
problem of being limited to searching files
of known suspects.
• Inauguration of a single-fingerprint file
using modifications of a method developed
by former Scotland yard Chief Inspector
Harry Battley.
Classification of Fingerprints
• The method utilized a special reticule, half
of which had a series of concentric circles
that were used to define specific areas of
scrutiny. Some pattern types were subdivided (arches into 5 categories) & ridge
counts for whorls were added.
• Additional work multiplied tenfold the work
for classificating fingerprints.
Classification of Fingerprints
• As a practical matter, files were kept only
for certain notorious criminals, repeat
felons, & those in certain categories such
as bank robbers & kidnappers.
• Since 1970, computer technology has
made it possible to automate the process
of fingerprint searching with the automated
fingerprint identification systems (AFIS).
Classification of Fingerprints
• A serial killer in Los Angeles with 15
murders was identified in about 20
minutes after AFIS was brought into
service.
• This would have taken about 67 years to
manually search through the fingerprint
files that AFIS did in under half an hour.
Identification of Fingerprints
• Method of comparison of fingerprints is to
use the ridge characteristics or minutiae
to individualize the print, establishing the
individuality or uniqueness of it.
• One should speak of identifying a marking
as a fingerprint but of individualizing a
fingerprint as that belonging to a particular
person.
Identification of Fingerprints
• Ridge characteristics or minutiae used to
individualize a fingerprint include those
used in AFIS.
• Ridge ending – termination point of a
friction ridge (end of friction ridge)
• Bifurcation – branching or forking of a
ridge into two ridges
Identification of Fingerprints
• Ridge dot: ridge feature that resembles a
period & is only about as long as it is wide.
• Enclosure: ridge characteristic resembling
eyelet caused by bifurcation legs coming
together again to form a single ridge.
• Short ridge: one whose terminal (end)
points are very close together.
Classification of Fingerprints
Identification of Fingerprints
• Trifurcation: branching into 3 bridges
• Bridge: or bar linking two ridges
• Creases: short white lines crossing ridges,
not considered minutiae because they are
impermanent features (not permanent)
• Scar: may be utilized as such for purpose
of comparing two prints
Identification of Fingerprints
• To actually make a comparison, expert
looks for 4 elements to match other print
so individualization may be declared.
• 1. Likeness of pattern – two prints must
have a likeness of pattern types – arches,
loops, etc.
• 2. Qualitative likeness of ridge minutiae –
ridge endings must match such as
enclosures, bifurcations, etc.
Identification of Fingerprints
• 3. Quantitative likeness of ridge minutiae –
sufficient # of ridge details present for
individualization to be declared.
• 4. Likeness of location of minutiae –
friction ridge details must be in same
relative position, same relative directions &
distance from each other & same # of
ridges between them in both fingerprints
Identification of Fingerprints
• There must be no unexplained differences
between prints
• Ten to twelve characteristics would
generally seem reasonable number in
most cases, fewer if points of comparison
are particularly distinctive
• If pores in ridges are visible, science of
poroscopy may be applied
Identification of Fingerprints
• Pores are also different from person to
person; are permanent & may serve as
basis for a positive individualization of one
print with another
• Comparator – imaging device placing two
greatly enlarged images side by side on
an illuminated viewing screen.
Identification of Fingerprints
• Modern electronic imaging technology
using digital photography can also provide
nearly instant enlargements of fingerprints
for comparative purposes
• For courtroom presentation, the known file
print & the questioned latent print are
compared side by side in greatly enlarged
form.
Identification of Fingerprints
• Standard method of demonstrating
similarity is to draw fine line from each
ridge characteristic to white space
surrounding the print & give each such
point its own number.
• Placement of lines & #s should be as
similar as possible on both prints. Usually
#s & names of features they represent are
listed on exhibit to avoid confusion
Identification of Fingerprints
• Footprints & palmprints are just as unique
as fingerprints & can be used as evidence
• Any area of the inner surface of the hands
or feet contains friction ridges and patterns
that are just as effective for comparison as
fingerprints.
• Only drawback is difficulty of recording
and classifying such impressions
Processing and Recovery
• Fingerprints may be recovered from a
crime scene in several forms. It is usual to
list three types of prints discussed
presently, but a fourth special type might
be considered as part of a gruesome
category such as dismembered fingers or
partial tears or dismemberments or even
parts of an ear
Processing and Recovery
• Plastic fingerprints: those impressed into
some substance such as wax, soap, putty
or even dust; 3-D depressions made by
friction ridges
• Visible prints: those left by fingers that
have been coated with some colored
substance such as blood, grease, paint,
dirt or ink
Processing and Recovery
• Latent fingerprints: “lie hidden” or are
relatively invisible & need some form of
processing or developing.
• Plastic & visible fingerprints may easily be
photographed, but latent prints require
careful handling. They are of a “delicate
nature”.
Processing and Recovery
• Surface must be able to retain the print
without absorbing & spreading it
• Hard, glossy objects (i.e. glass & enamel
painted walls/doors) present ideal surfaces
• Dirty surfaces & absorbent materials do
not readily bear prints
• Fingerprint must be deposited with right
amount of pressure
Processing and Recovery
• Object must not be touched with an
excess of pressure. This tends to spread
the print.
• Person’s fingers must have certain degree
of moisture or should have some body
grease on ridges.
• When all these requirements are fulfilled a
god latent fingerprint is deposited.
Processing and Recovery
• Thin film of latent fingerprint contains
substances - predominantly perspiration,
secreted by pores in friction ridges, &/or
body oils acquired by contact with other
parts of the body notably the hair and face
• Perspiration made up of moisture, salt,
amino acids, dead epidermal cells, and
various foreign substances
Processing and Recovery
• Decision regarding what treatment should
be used to develop a latent print depends
largely on the surface on which it lies,
experience with the substances in the
prints and the technology available.
• Searching for fingerprints is conducted by
specially trained personnel
Processing and Recovery
• Wearing light cloth gloves while collecting
evidence is recommended although some
experts use disposable latex gloves.
• One authoritative source recommends
against gloves entirely since they invite
carelessness that may destroy prints or
leave glove prints that mislead others.
Processing and Recovery
• Objects should be handled minimally & by
edges or by surfaces unreceptive to prints
• Fingerprint expert should be given priority
access to objects such as firearms &
documents over other criminalists
• Any articles removed from scene must be
correctly labeled & carefully transported to
prevent destruction of prints
Processing and Recovery
• In looking for fingerprints, flashlight &
magnifying glass represent standard
equipment.
• Beam of flashlight at an acute angle to
surface may help reveal latent
impressions.
• Examining surface from various angles
may accomplish same purpose
Processing and Recovery
• When a plastic or visible fingerprint is
discovered, it should be photographed in
situ, as should a latent impression after it
is developed
• Approach for latent prints discovered on
nonporous surfaces begins with visual
search & if necessary search with more
sophisticated light sources: argon laser
beam causing latent print to fluoresce
Processing and Recovery
• Using lasers to detect latent prints is clean
-no pretreatment of specimen is required no alteration of evidence. Therefore it is
used 1st & conventional methods used 2nd
• RUVIS: Reflected Ultraviolet Imaging
System makes use of wavelengths beyond
those of visible light; can reveal latent
impressions that might otherwise go
undetected
Processing and Recovery
• Following laser detection on nonporous
surface, next step for relatively small
objects is to develop print using
cyanoacrylate vapor – a.k.a. “Superglue”
• Technique was brought from Japan to US
by Ed German & Paul Norkus of U.S.
Army crime lab & improved in 1982 by
Frank Kendall by adding sodium hydroxide
Processing and Recovery
• Fuming process is carried out in an airtight
tank.
• Instead of fuming or in addition to it,
fingerprint expert may use a brush to apply
fingerprint powders.
• Standard powders are lampblack for use
on light-colored surfaces & titanium oxide
for dark surfaces.
Processing and Recovery
• Colored powders such as dragon’s blood
are used for certain special situations.
• Alternatively, a magnetic-sensitive powder
is applied with magnet - Magna Brush.
Since no brush bristles, less chance print
will be damaged.
• Special fluorescent powders used with
laser or other forensic light sources
Processing and Recovery
• Reason for using first the forensic light
sources, then chemical fuming, & finally
dusting with powders is to be as nondestructive as possible.
• Powder may result in smudging or overprocessing the print & once it is used,
other procedures are generally precluded
Processing and Recovery
• After a print is developed by powdering, it
may be lifted with special transparent tape
& then protected with a stiff, transparent
cover
• Since lifting process is somewhat risky &
may damage or distort print, impression
should be photographed before lifting tape
is applied
Processing and Recovery
• Porous surfaces such as paper, cardboard
& unpainted wood present more difficulty.
• With such surfaces, powders should be
avoided since they tend to adhere to the
background surface as well as the print.
• Following visual & fluorescent
examination, you can use chemical
treatment with ninhydrin to develop latent
impressions that might be present
Processing and Recovery
• Other techniques used for porous
materials include application of a solution
of silver nitrate or other silver based
solution called “physical developer”.
• For developing prints on wet surface, a
material called “small particle reagent”
may be used
Processing and Recovery
• One of most difficult surfaces to develop
fingerprints on (yet one of the most useful
as probative evidence) is human skin
• The fact that murderers frequently grab
their victims makes it desirable for
homicide investigators to develop
identifiable fingerprints from the corpse’s
skin
Processing and Recovery
• Problem developing skin fingerprints is
they contain same substances as human
skin does.
• Most effective procedure is cyanoacrylate
fuming technique & applying magnetic
fingerprint powder
Processing and Recovery
• Because of condensation on refrigerated
bodies, it is recommended that prints be
recovered before the body is refrigerated if
possible. Otherwise, the process should
be delayed while any moisture evaporates
• Enhancing fingerprints can be done using
programs such as Adobe Photoshop to
improve sharpness & contrast.
Case Study: Aileen Wuornos
Female Serial Killer
• Gives evidentiary value to fingerprints.
• Female lesbian prostitute who shot her
victims whether or not they picked her up
as a prostitute or not
• Watch A & E movie “Death Row Prostitute”
and answer video quiz questions.