Notes Ch. 14 Fingerprints

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NotesCh. 14 Fingerprints
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I. History of Fingerprints

• Police have always looked for a foolproof method
  of human identification.
• 1st system Bertillon 1883 called anthropometry

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A. Early Use of Fingerprints

• Chinese 1000 B.C. used F.P. to sign legal
  documents
• 2. 1880 Fauld and Herschel suggested that
  fingerprints are useful for ID criminals

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B. Early Classification of Fingerprints

• Galton, in 1892, published Finger Prints
• Demonstrated no 2 F.P. are identical
• Showed individuals F.P. remain unchanged in life
• Proposed 3 F.P. categories
• 1. Loops (60)
• 2. Whorls (30-35)
• 3. Arches (5-10)

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• 2. Development of Classification System
• a. Dr. Juan Vucetich-Argentina
• 1891 (still used in most Spanish
• speaking countries today)
• b. Sir Edward Henry-England
• 1897 (used in U.S., England, etc.)

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C. Adoption of Fingerprints

• 1901-New York City adopted F.P.
• 1903-Prison Twins
• -2 criminals looked and measured identically
• -fingerprints were very different
• 3. 1904-Worlds Fair Police trained by Scotland
  Yard

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II. Fundamental Principles of F.P.

• First Principle
• -A F.P. is an individual characteristic
• -No two fingers have yet been found to possess
  identical prints
• Currently 60 million F.P. in FBI database

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• I.D. of fingerprints based on Ridge
  Characteristics (a.k.a. minutaie)
• Ridge Characteristics
• A. bifurcation
• B. ridge ending
• C. ridge island
• D. enclosure
• E. short ridge
• F. bridge
• G. Crossover
• H. Spur (hook)

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Lets practice!

• Take out a pen (blue or black ink) and clear
  everything else off your desk.
• Balloon prints

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B. Second Principle

• 1. A fingerprint remains unchanged during an
  individuals lifetime

a. Fingerprints develop at 3 months gestation.
b. Many criminals have tried to alter/eliminate
them.
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2. Shape of dermal papillae determines form and
pattern of ridges

• Papillae are cells that separate epidermis from
  dermis.

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C. Third Principle

• Fingerprints have general ridge patterns that
  permit them to be systematically classified
• General patterns
• loops (60-65 of population)
• 1. ulnar loop 2. radial loop
• B. whorls (30-35)
• 1. plain whorl 2. central pocket whorl
• 3. accidental whorl 4. double loop whorl
• C. arches (5)
• 1. plain arch 2. tented arch

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III. Classification of Fingerprints
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A. Fingerprint Vocab

• 1. Core center of the fingerprint
• 2. Delta triangular area

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B. Specific Types of Fingerprints

• Two Types of ARCHES

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Arch-all lines enter and exit from opposite sides
of finger
2. Tented Arch-drastic spike
1. Plain Arch-rolling hill
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2 Types of Loops
Loop-only one delta at least one ridge line
enters and exits same side of print
Must know which hand you are looking at to
determine!!
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4 Types of Whorls
whorl-2 deltas at least one ridge line does not
exit finger
2. Central Pocket Loop Whorl-line btwn deltas
does not intersect full circles

• 1. Plain Whorl-line between deltas intersects
  circles

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Practice

• Plain whorl or central pocket loop whorl?

ANS Central pocket loop whorl
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Practice

• Plain whorl or central pocket loop whorl?

ANS Plain whorl
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More Whorls
4. Accidental whorl- characterized by 3 deltas
frowny face

• 3. Double loop whorl looks like yin yang

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Accidental Whorls 2 or more types of prints
More Examples
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Practice

• Double loop whorl or accidental whorl?

ANS double loop whorl
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Practice

• Double loop whorl or accidental whorl?

ANS accidental whorl
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Lets practice!

• Please take your Unit 2 classwork paper.
• Date 9/22/14
• Title WS Classification of FP 2

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C. Fingerprint Classification Code

• 1. Every print is given a code after it enters
  the F.P. database
• 2. 1st classification step called the primary
  classification
• 3. Code is based on presence or absence of whorl
• 4. Approximately 25 of the population falls into
  the 1/1 category (they do not have any whorls)

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

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Example 1

• Suspect F.P.

Finger Left Right
Thumb Arch Loop
Index Loop Loop
Middle Whorl Arch
Ring Loop Loop
Little Arch Whorl

0 0
0 0
2 0
0 0

0 4
1 1
3 5

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Example 2

• Suspect F.P.

Finger Left Right
Thumb Arch Whorl
Index Loop Loop
Middle Loop Arch
Ring Loop Whorl
Little Arch Arch

0 16
8 0
0 0
0 0

0 0
1 1
9 17

Do not reduce fraction 2/4 stays as 2/4
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Practice
Take out Unit 2 Classwork paper. Date
9/23/14 Title FP Code Practice

• Find your own classification code.
• Determine your partners classification code.
• Compare your answers.

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D. AFIS

• AFIS Automated Fingerprint Identification
  System
• FBI has largest
• Some cities, counties, states have their own that
  may or may not link to FBI
• Converts image of fingerprint into digital scan
  with reference points to ridge endings and
  bifurcations

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III. 3 Types of Crime Scene Prints

• Visible-can be seen by naked eye
• Ex prints left in blood, paint, dust,
  grease, ink
• Plastic-occurs when ridge impressions are left in
  soft material
• Ex prints left in wax, play-doh, soap, puddy
• Latent (Invisible)-not seen by naked eye caused
  by a transfer of oils onto surface

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IV. Methods for Developing Latent Prints

• Super Glue Fuming-nonporous materials
• Dusting-nonporous materials
• Iodine Fuming-porous materials
• Ninhydrin-porous materials
• Physical Developer-porous materials

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V. Locating Fingerprints

• Visible and plastic easy to see
• Latent RUVIS (reflected ultraviolet imaging
  system)
• aims UV light at a surface suspected of having
  prints
• Light is converted into visible light

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VI. Proper Collection of F.P.

• Step 1 Location documented, object photographed
• Step 2
• Small Object taken back to lab, F.P. developed
  there
• Large Object F.P. developed and lifted at crime
  scene