LATENT PRINTS

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FINGERPRINTS
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FINGERPRINTS

• Introduction
• Most widely used of personal identification
  techniques
• Involves the study and classification of
  fingerprints
• The development of latent prints
• Comparison of known and unknown fingerprints.

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FINGERPRINTS

• Objectives
• Understand the anatomy of skin as it relates to
  fingerprints
• Fingerprint classification systems
• Fingerprint characteristics
• Development of latent prints

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FINGERPRINTS

• The Anatomy of Skin
• 3 layers
• The Epidermis
• The Dermis
• The Hypodermis
• Each ridge of the epidermis (outer skin) is
  dotted with sweat pores and is anchored to the
  dermis (inner skin).

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FINGERPRINTS

• RIDGE arrangement on every finger of every human
  being is unique
• Fingerprints serve to reveal an individual's true
  identity despite personal denial, assumed names,
  or changes in personal appearance resulting from
  age, disease, plastic surgery, or accident

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FINGERPRINTS

• The Anatomy of Skin
• 3 layers
• The Epidermis varies in thickness depending on
  the body area and contains no blood vessels
• The Dermis a thick layer of connective tissue
  that contains blood vessels and provides
  nutrients and blood to the epidermis

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FINGERPRINTS

• The Anatomy of Skin
• The skins appendages or accessory structures are
  embedded in the epidermis and dermis. The
  accessory structures include
• Hair follicles
• Sweat glands
• Sebaceous glands
• Nails

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FINGERPRINTS

• The Anatomy of Skin
• The Hypodermis the subcutaneous tissue that
  lies below the dermis, and consists of connective
  tissue, fat cells, macrophages, fibroblasts,
  blood vessels, nerves and the base of the
  accessory glands

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FINGERPRINTS

• Functions of the Skin
• Provides the first line of defense against
  invasion by microorganisms and foreign materials
• Inhibits excessive fluid loss
• Important in controlling body temperature
• Sensory functions

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FINGERPRINTS

• How Made
• Formed from the RIDGES and GROOVES on the tips of
  fingers, toes, and palms, which are generated
  from the DERMAL LAYER of the skin PRIOR TO BIRTH
  and are totally unique to that person. 

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FINGERPRINTS

• Alphonse Bertillion
• French Police Officer
• Devised and introduced the first systematic
  attempt at personal ID based on body types in
  1883

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FINGERPRINTS

• In 1880, Dr. Henry Faulds began a study of
  skin-furrows after noticing the finger marks on
  certain pieces of artifacts.
• Suggested that skin ridge pattern could be
  important for the ID of criminals.

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FINGERPRINTS

• Francis Galton
• 1892 Book on Fingerprints
• Naming 3 patterns
• Loop
• Arch
• Whorl
• Demonstrated that no two are unlike
• Fingerprints remain unchanged

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FINGERPRINTS

• 1893 - Dr. Juan Vucetich - Argentine police
  officer
• His classification system has been refined over
  the years and is still widely used today in most
  Spanish-speaking countries.

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FINGERPRINTS

• 1897, Sir Edward Richard Henry
• The fingerprinting bureau - founded at Scotland
  Yard in 1901
• Today, most English-speaking countries, including
  the US, use a version of Henrys system to file
  fingerprints.

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FINGERPRINTS

• In 1903, when the Bertillion system could not
  distinguish between two men (one Will West and
  the other William West), it was fingerprinting
  that clearly distinguished them.
• After the Will West incident, the use of
  fingerprinting by the New York City Civil Service
  Commission in 1901, and the training of American
  police by Scotland Yard representatives at the
  1904 Worlds Fair, fingerprinting began to be
  used in earnest in all major U.S. cities.

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FINGERPRINTS

• Fingerprint Classification
• 3 basic principles
• Fingerprints are an individual characteristic
• They remain unchanged throughout a persons
  lifetime
• They have general ridge patterns (friction
  ridges) that allow them to be classified and used
  in personal ID

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LATENT PRINTS

• An important part of a forensic investigation is
  the identification of the victim or suspect. One
  of the most useful identification tools is the
  fingerprint pattern.

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Classification of Fingerprints
FINGERPRINTS
Arch Loop Whorl
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FINGERPRINTS

• Fingerprints are classified in a three-way
  process
• By the shapes and contours of individual patterns
  
• By noting the finger positions of the pattern
  types
• By relative size, determined by counting the
  ridges in loops and by tracing the ridges in
  whorls

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FINGERPRINTS

• Ridge Patterns
• 3 Basic types
• Loops 60
• Whorls 35
• Arches 5

Population Distribution of Ridge Patterns
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Fingerprint Patterns
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FINGERPRINTS

• In this picture the technician is demonstrating
  the location of ridge endings, bifurcations and
  dots.

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PRINCIPAL ONE

• After a three year study, it was determined that
  no valid basis exists for requiring a
  predetermined minimum number of friction ridge
  characters which must be present in two
  impressions in order to establish positive
  identification.
• In a judicial proceeding, an expert must
  demonstrate a point-by-point comparison in order
  to prove the identity of an individual.

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PRINCIPAL TWO

• The dermal papillae is the layer of cells between
  the epidermis and dermis, that is responsible for
  determining the form and pattern of the ridges on
  the surface of the skin.
• Once the dermal papillae develop in the human
  fetus, the ridge patterns will remain unchanged
  throughout life except to enlarge during growth.
  Thus, a fingerprint will remain unchanged during
  an individuals lifetime.

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PRINCIPAL TWO

• Each skin ridge is populated with pores leading
  to sweat glands from which perspiration is
  deposited on the skin.
• Once the finger touches a surface, perspiration,
  along with oils that may have been picked up by
  touching the hairy portions of the body, is
  transferred onto that surface, leaving the
  fingers ridge pattern (a fingerprint).

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PRINCIPAL THREE

• All fingerprints are divided into three classes
  on the basis of their general pattern loops,
  arches, and whorls (L.A.W.).
• A loop must have one or more ridges entering from
  one side of the print, recurving, and exiting
  from the same side.
• If the loop opens toward the little finger, it is
  called an ulnar loop.
• If the loop opens toward the thumb, it is called
  a radial loop.
• All loops must have one delta, which is the ridge
  point at or directly in front of the point where
  two ridge lines (type lines) diverge.

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PRINCIPAL THREE

• Whorls are divided into four groups plain,
  central pocket loop, double loop, and accidental.
• All whorl patterns have type lines and a minimum
  of two deltas.
• A plain whorl and a central pocket loop have at
  least one ridge that makes a complete circuit.
• The double loop is made up of two loops combined
  into one fingerprint.
• An accidental either contains two or more
  patterns, or is a pattern not covered by the
  other categories.

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PRINCIPAL THREE

• Arches, the least common of the three general
  patterns, are divided into two distinct groups
  plain arches and tented arches.
• The plain arch is formed by ridges entering from
  one side of the print, rising and falling, and
  exiting on the opposite side (like a wave).
• The tented arch is similar to the plain arch
  except that instead of rising smoothly at the
  center, there is a sharp upthrust or spike, or
  the ridges meet at an angle that is less than 90
  degrees.
• Arches do not have type lines, deltas, or cores.

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THE LOOP

• The LOOP is a classification of fingerprints
  characterized by ridge lines that enter from one
  side of the pattern and curve around to exit from
  the same side if the pattern.
• A loop MUST have
• One of more ridges entering from one side of the
  print and re-curve and then exit from the same
  side.
• -Ulnar Loop -Radial Loop
• -Delta -Core

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THE WHORL

• The WHORL is a class that includes ridge patterns
  that are generally rounded or circular in shape
  and have two deltas.
• Divided into 4 groups
• Plain Whorls
• Central Pocket Loop
• Double Loop
• Accidental

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THE ARCH

• The ARCH is a classification of fingerprints
  characterized by ridge lines that enter the print
  from one side and flow to the other side.
• Two types
• Plain
• Tented
• Arches do not have type
• lines, deltas, or cores.

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Fingerprint Ridge Characteristics
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Fingerprint ridge characteristics. Courtesy
Sirchie Finger Print Laboratories, Inc.,
Youngsville, N.C., www.sirchie.com.
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A fingerprint exhibit illustrating the matching
ridge characteristics between the crime-scene
print and an inked impression of one of the
suspects fingers. Courtesy New Jersey State
Police.
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Figure 145  Loop pattern.
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Whorl patterns.
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Arch patterns.
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PALM PRINTS
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LATENT PRINTS

• HENRY SYSTEM -
• Converted ridge patterns into letters and numbers
  in the form of a fraction
• Too cumbersome for large of patterns
• Due to this, and the need to file millions of
  fingerprint cards at the FBI, a modified Henry
  System was implemented.

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LATENT PRINTS

• The FBI system
• A system based on an applied classification
  formula
• Based on a series of modifications and extensions
  of the Henry System

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PRIMARY CLASSIFICATION

• Fingerprint classification systems are based on
  knowledge of fingerprint pattern classes.
• First, fingers are paired up, placing one finger
  in the numerator of a fraction and the other in
  the denominator.
• The presence or absence of the whorl pattern is
  the basis for the determination of the primary
  classification.
• If a whorl pattern is found on any finger of the
  first pair, it is assigned a value of 16 on the
  second pair, an 8 on the third pair, a 4 on the
  second pair, a 2 and on the last pair, a 1.
• Any finger having a loop or arch is assigned a 0.

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PRIMARY CLASSIFICATION

• After values for all 10 fingers are obtained,
  they are totaled, and a 1 is added to both the
  numerator and denominator.
• The fraction thus obtained is the primary
  classification.
• Approximately 25 of the population falls into
  the 1/1 category that is, all their fingers have
  either loops or arches.
• A fingerprint classification system cannot in
  itself unequivocally identify an individual it
  will merely provide the fingerprint examiner with
  a number of candidates, all of whom have an
  indistinguishable set of prints in the systems
  file.

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LATENT PRINTS

• R. Index (16)
• R. Thumb
• R. Ring (8)
• R. Middle
• L. Thumb (4)
• R. Little
• L. Middle (2)
• L. Index
• L. Little (1)
• L. Ring

• Primary Classification - the first classification
  method that allowed all fingerprint cards to be
  divided into 1024 groups. It was based on the
  presence or absence of a whorl pattern.

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LATENT PRINTS

• The FBI system
• radial loop
• ulnar loop
• double loop
• central pocket loop
• plain arch
• tented arch
• plain whorl
• accidental

• Primary Classification
• Can divide all the fingerprints in the world into
  1024 groups
• Not widely used
• http//www.nifs.com.au/FactFiles/Fingerprints/how.
  asp?pagehow

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LATENT PRINTS

• Major Fingerprint
• Characteristics
• Typelines
• Deltas
• Cores

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LATENT PRINTS

• Surface Print
• the same fingerprint as it would be detected on
  a surface.

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LATENT PRINTS

• Classification of Loops
• Delta
• Sufficient recurve
• Ridge count
• Radial/ulnar loops

• Classification of Arches
• Plain arches
• Tented arches
• Angular
• Up thrust

http//155.217.58.58/cgi-bin/atdl.dll/fm/19-20/ch7
.htms8 http//biometrics.cse.msu.edu/fingerprint.
html Websites show an array of fingerprint
patterns.
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LATENT PRINTS

• Fingerprint Impressions
• Inked Fingerprint Examination Fingerprints from
  the Living!
• Start with clean hands not just yours!

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LATENT PRINTS

• Rolled Impressions
• Plain Impressions
• Palm Prints
• Major Case Prints

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LATENT PRINTS

• Obtaining Impressions from Corpses
• Major Case Prints are always obtained from
  corpses
• Used to identify or eliminate latent print
  evidence
• Identification of the deceased

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LATENT PRINTS

• Dusting For Prints
• Latent Fingerprint Development
• Means to develop latent prints include
• Processing evidence and other surfaces using
  powders, chemicals and specialized lighting
  techniques

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LATENT PRINTS

• Friction Ridges
• Latent Prints- Some impressions are easily seen
  (called patent prints) and others can only be
  seen with specialized techniques and are called
  latent prints.

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LATENT PRINTS

• Indented Prints - prints that are easily seen
  embedded in some type of soft surface, such as
  putty, plaster, sand or candle wax.

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LATENT PRINTS

• Techniques of Print Processing
• At the Crime Scene
• examine all surfaces and objects
• photograph and collect all indented and visible
  prints

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LATENT PRINTS

• The visibility of latent prints depends on
  numerous factors
• The physical condition of the person who left the
  print
• The surface of the object
• Lighting angles
• The time since the prints were placed
• Amount of heat to which they have been exposed

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LATENT PRINTS

• The amount of time prints remain on an object is
  affected by
• Weather
• Air currents
• Humidity

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LATENT PRINTS

• Latent print evidence is divided into two
  categories
• Porous
• paper, unfinished wood, cardboard
• Non-porous
• plastic, glass, metal, foil

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LATENT PRINTS

• Porous evidence - paper, unfinished wood,
  cardboard
• Usually preserved well because print residue can
  soak into the surface

Iodine Fuming
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NinhydrinPhysical Developer
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LATENT PRINTS

• Non-porous sample
• Thumbprint found on metal latch

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LATENT PRINTS

• Powdering
• Use the powder that provides the best contrast
  with the background for photography purposes, but
  black and white are typically used
• Applied with brushes and other application
  instruments (magnetic wands, cotton fabric).

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LATENT PRINTS

• Regular Powders
• Most commonly used for processing prints on
  windows, counter-tops, television sets, metal
  file cabinets, painted doors, mirrors, broken
  glass and metal window frames.

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LATENT PRINTS

• Magnetic Powders
• Special surfaces i.e.,
• shiny magazine covers
• coated surfaces
• plastic storage or sandwich bags

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LATENT PRINTS

• Fluorescent powders
• Regular or magnetic
• Observe the development of the latent prints
  with a UV light source while applying the
  powders.

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LATENT PRINTS

• Lifting
• Rubber lifters - lifting prints from curved or
  uneven surfaces
• Transparent lifting tapes Reversed print

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LATENT PRINTS

• Chemical Processing
• Done at the laboratory
• Preferred method with porous surfaces

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LATENT PRINTS

• Physical Development Technique
• Small Particle Reagent (SPR)
• can be used on
• Paper, cardboard
• New, rusty, galvanized metal
• Bricks, rocks, concrete,
• Plastic, vinyl
• Wood
• Glass.

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Super Glue Fuming
Super glue fuming print
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LATENT PRINTS

• Chemical Development Techniques
• Ninhydrin - porous surfaces (paper, cardboard,
  and wood)
• Diazafluoren (DFO)- 2.5x more sensitive than
  Ninhydrin alone
• Sticky Side Powder - adhesive tapes labels
• Iodine Fuming - paper surfaces, and hard smooth
  surfaces
• Cyanoacrylate Fuming - super glue

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LATENT PRINTS

• Dye Stains
• Sudan Black- develop latent prints on smooth or
  rough, nonporous surfaces contaminated with
  greasy, oily and sticky substances

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LATENT PRINTS

• Other Dyes
• Ardrox Fluorescent Dye UV lamp
• TapeGlo Fluorescent Dye
• Amido Black - sensitive to blood proteins
• Crystal Violet
• Physical developer (PD)

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LATENT PRINTS

• Mechanical Methods
• Electrostatic Detection Apparatus (ESDA)
• X-ray Detection (lead powder)
• Vacuum Metal Deposition

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LATENT PRINTS

• Surface Effects -The use of two or more methods
  in a sequence of processing techniques.
• Sequencing of Print Development (Smooth)
• Visual examination using necessary light
• Examination with specialized light sources (UV)
• Dust with non-magnetic powder
• Magnetic powder dusting and or fluorescent powder
  
• Fluorescent Dye staining

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LATENT PRINTS

• Sequencing of Print Development (Porous surfaces)
  
• Visual examination
• Fluorescent examination
• Iodine fuming
• Magnetic powder
• DFO
• Ninhydrin
• PD

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LATENT PRINTS

• Latent Prints on Skin - can be washed away with
  water excreted through perspiration. With
  homicide victims, the skin has often been exposed
  to harsh conditions, such as mutilation,
  contamination with body fluids, weather effects,
  and decomposition

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LATENT PRINTS

• Latent Prints in Blood -
• Leuchomalachite Green - used to stain
  fingerprints in blood that can be photographed
• Amido Black - traditional treatment for blood
  prints.
• Chemical processing should only be carried on
  blood if visual techniques fail

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AFIS (Automated Fingerprint Identification
Systems)

• The Integrated Automated Fingerprint
  Identification System, (AFIS)
• National fingerprint and criminal history system
  maintained by the Federal Bureau of Investigation
  (FBI), Criminal Justice Information Services
  (CJIS) Division.

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Automated Fingerprint Identification Systems

• The introduction of AFIS in 1997 has allowed
  fingerprint techs to scan fingerprint images into
  the database for easy storage, retrieval, and
  comparison.

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AFIS (Automated Fingerprint Identification
Systems)

• The AFIS provides automated fingerprint search
  capabilities, latent searching capability,
  electronic image storage, and electronic exchange
  of fingerprints and responses, 24 hours a day,
  365 days a year.

• As a result of submitting fingerprints
  electronically, agencies receive electronic
  responses to criminal ten-print fingerprint
  submissions within two hours and within 24 hours
  for civil fingerprint submissions.

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Automated Fingerprint Identification Systems

• LiveScan Fingerprinting
• LiveScan is inkless electronic fingerprinting.
  The fingerprints are electronically transmitted
  to the Department of Justice (DOJ) for completion
  of a criminal record check.

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Digital Imaging for Fingerprint Enhancement

• Technology can enhance the condition of the
  prints, which are lifted from the crime scene
• The advancements in computers has greatly
  improved the fingerprint identification process
• Software has been developed which can now
  accurately analyze the print and eliminate
  unwanted background materials, which can impede
  the latent images

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Automated Fingerprint Identification Systems

• A trained technician scans your fingerprints
  using an Identix TouchPrint 600 LiveScan. The
  electronic fingerprinting appointment takes five
  to ten minutes and your prints are
  immediately available for electronic
  transmission to the appropriate
  FBI-Certified channeling agencies for background
  processing.

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Automated Fingerprint Identification Systems

• AFIS has changed the way criminal investigators
  operate, allowing them to spend less time
  developing suspect list and more time
  investigating the suspects generated by the
  computer.
• The AFIS makes no final decisions on the identity
  of a fingerprint, leaving this function to the
  eyes of a trained examiner.

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Automated Fingerprint Identification Systems

• What are the benefits of LiveScan?
• Live Scan will avoid many of the problems
  associated with ink prints, such as smudging,
  smearing, and over or under inking.
• A major benefit of Live Scan is in processing
  speed since nearly all of those without criminal
  records are done within 72 hours and up to 30
  days if there is a criminal record.
• Rolled ink prints (traditionally submitted on a
  fingerprint card) can take 10 to 12 days to
  process (plus mail time) and up to 60 days if
  there is a criminal record.

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FingerPrint Humor
John Dillinger tried to burn off his fingerprints
with acid but even this failed to do so!
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FINGERPRINTS
The End