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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 1
Chapter 14Fingerprints
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 2
History• Alphonse Bertillion
– French police expert– First systematic attempt at personal
identification was• Bertillion system
– Relied on a detailed description of the subject
– Combined with full length and profile photographs
– System of precise body measurements called anthropometry
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 3
History
• Francis Galton– 1892– Classic textbook finger prints
• At Galton’s insistence– British government adopted fingerprinting– Supplement to the bertillion system.
• Next step– Creation of classification systems– Capable of filing many thousands of prints– Logical and searchable sequence.
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 4
History• Dr Juan Vucetich
– Devised a classification system– Still used in most spanish-speaking countries
• Sir Edward Henry: system used in most English-speaking countries.
• Will West and William West case– 1903– Bertillion system could not distinguish between
men– Fingerprinting that clearly distinguished them
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 5
History• Fingerprinting used by the New
York city civil service commission in 1901
• Training of American police by Scotland yard representatives at the 1904 world’s fair
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 6
Fingerprint Principles
Reproduction of friction skin ridges Palm side of the fingers
& thumbs
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 7
Fingerprint Principles• Individual characteristic
– Because no two fingers with with identical ridge characteristics
• Remains unchanged during an individual’s lifetime
• General ridge patterns that permit systematic classification
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 8
Principle One
Individual CharacteristicNo Fingers Identical
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 9
Principle One• Mathematical probability for
existence of two identical fingerprint patterns in the world’s population = almost zero
• Millions upon millions of individuals who have had their prints classified–No two fingerprints have been
found to be identical
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 10
Figure 14–1 Fingerprint ridge characteristics. Courtesy Sirchie Finger Print Laboratories, Inc., Youngsville, N.C., www.sirchie.com.
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 11
Principle One• Individuality of fingerprint not
determined by its general shape or pattern
• Careful study of its ridge characteristics, known as minutiae.– Identity, number, and relative
location – Individuality to a fingerprint.
• As many as 150 minutiae on the average finger
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 12
Principle One• Three year study
– “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”
• Judicial proceeding– Expert must demonstrate a point-
by-point comparison– To prove the identity of an
individual
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 13
Figure 14–2 A fingerprint exhibit illustrating the matching ridge characteristics between the crime-scene print and an inked impression of one of the suspect’s fingers. Courtesy New Jersey State Police.
Fingerprint Comparison
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 14
Principal Two
Remains Unchanged During Lifetime
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 15
Principal Two• Epidermis
– Outer layer of the skin
• Dermis– Inner layer of the
skin
• Dermal papillae– Layer of cells
between the epidermis and dermis
– Responsible for determining the form and pattern of the ridges on the surface of the skin
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 16
Principal Two• Dermal papillae
develop in the human fetus
• Ridge patterns will remain unchanged throughout life
• Enlarge during growth
• Fingerprint remains unchanged during lifetime
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 17
Principle Two• Skin ridge is
populated with pores leading to sweat glands
• Perspiration is deposited on the skin
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 18
Principle Two•Finger touches a surface–Perspiration–Oils from hairy portions of the body
–Transferred onto surface•Leaves fingerprint
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 19
Principle Three
Ridge Patterns Permit Systematic Classification
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 20
Principle Three•All fingerprints– divided into three classes – Loops–Arches–whorls – L.A.W.
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 21
Loop Patterns
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 22
Principle Three - Loops• 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.
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 23
Figure 14–5 Loop pattern.
Principle Three - Loops
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 24
Principle Three - Loops• Must have one
delta• Ridge point at or
directly in front of the point where two ridge lines (type lines) diverge
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 25
Whorls
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 26
Principle Three- Whorls• Divided into four groups–Plain–Central pocket loop–Double loop–Accidental
• All have type lines and minimum of two deltas
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 27
Whorls• Plain whorl and central pocket loop have at
least one ridge that makes a complete circuit• Double loop: two loops combined into one
fingerprint• Accidental
– Two or more patterns– Or pattern not covered by the other categories
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 28
Plain Whorls• More than 1 valid delta • If you look at image A you should be
able to identify the two delta's. If not then look at image B and you will see that they are displayed in the red boxes.
• Whorl: one or more ridges which make complete circuit
• Two delta's– Between which an imaginary line is
drawn– At least one recurving ridge within the
inner pattern area cut or touched.
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 29
Plain Whorls
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 30
Whorls• Inner area of the pattern forms
circle or oval• Specific ridges that are making
or trying to make the circle– Imaginary line between the
two delta's (the red line in image)
–No lines that form the circle are intersected
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 31
Whorls
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 32
Arches
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 33
Principle Three - Arches• Least common of
general patterns–Plain arches–Tented arches
• No lines that form the circle are intersected
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 34
Plain Arches• Ridges entering from one side of
the print• Rising and falling• Exiting on the opposite side• Like a wave
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 35
Tented Arches• Sharp upthrust
or spike• 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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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 36
Primary Classification• Based on knowledge of
fingerprint pattern classes• Fingers are paired up–One finger in the numerator of
a fraction–Other in the denominator
• Presence or absence of the whorl pattern–Basis for the determination of
the primary classification
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 37
Primary Classification• Whorl pattern
– Any finger of the first pair value = 16
– On the second pair value = 8– On the third pair value = 4– On the second pair value = 2– On the last pair value = 1
• Any finger having a loop or arch value = 0
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 38
Primary Classification• Values for all 10 fingers totaled• 1 is added to both the numerator
and denominator• Fraction obtained is primary
classification.
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 39
Primary Classification• 25 percent of the population
– 1/1 category– All fingers loops or arches
• Cannot in itself unequivocally identify an individual
• Provides the fingerprint examiner with a number of candidates
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 40
AFIS
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 41
AFIS• Computer to scans, digitally
encodes fingerprints• Can be high-speed computer
processed
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 42
AFIS• AFIS aids in classifying and
retrieving fingerprints–Converts image of a fingerprint
into digital minutiae –Contain data showing ridges at
their points of termination (ridge endings) and their branching into two ridges (bifurcations).
• Thousands of comparisons per second
• Produces a list of file prints to be examined by a trained fingerprint expert
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 43
Visible & Latent Prints
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 44
Latent Prints• Invisible fingerprints• Finger touches a surface• Body perspiration and/or oils
present• Transferred to that surface• Leaves impression• Invisible to the eye
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 45
Visible Prints• Fingers touch a surface after contact
with a colored material such as blood, paint, grease, or ink
• Plastic prints: left on a soft material, such as putty, wax, soap, or dust
• Little problem to the investigator• Usually distinct and visible to the eye.
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 46
Detecting Prints
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 47
Detecting Prints• Hard nonabsorbent surfaces–Glass, mirror, tile, painted
wood–Developed by the application
of a powder• Porous surfaces–Papers, cardboard, and cloth–Require treatment with a
chemical
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 48
Ninhydrin• Reacts chemically with trace
amounts of amino acids• Produces a purple-blue color• Messy and stains skin badly
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 49
Physical Developer• Silver nitrate-based reagent• Used when other chemical
methods are ineffective• Silver nitrate solution stain
skin
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 50
Super Glue®
• Nonporous surfaces –Metals, electrical tape, leather,
plastic bags –Fumes from the glue adhere to
the print–Produce white latent print
• 98 to 99 percent cyanoacrylate ester
• Super Glue fuming– Fuming chamber (for up to six hours)– Handheld wand that heats a small
cartridge containing cyanoacrylate
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 51
Reflected UV Imaging System
•RUlVIS•No chemicals or powder•Locate With light source• investigator develops the
print in the most appropriate fashion
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 52
Figure 14–17 Schematic depicting latent-print detection with the aid of a laser. A fingerprint examiner, wearing safety goggles containing optical filters, examines the specimen being exposed to the laser light. The filter absorbs the laser light and permits the wavelengths at which latent-print residues fluoresce to pass through to the eyes of the wearer. Courtesy Federal Bureau of Investigation, Washington, D.C.
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 53
Powders•Powders, available in a
variety of colors, can be applied with a brush or magnetic wand, and adhere to perspiration and/or body oils of the print.
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 54
Iodine Fuming• Molecular iodine solid at room
temperature• Heat iodine crystals• Iodine vapors • Combine with latent prints to
make them visible– Iodine prints are not permanent– Will fade– Must photograph the prints
immediately
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 55
Fluorescence• High sensitivity• New chemical techniques used to
visualize latent fingerprints• Fingerprints treated with
chemicals – Induce fluorescence when
exposed to lasers–High-intensity light sources
(“alternate light sources”)–Quartz halogen, xenon arc, or
indium arc light sources.
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 56
Preservation of Prints•Visualized latent print•Permanently preserved–Future comparison–Possible use as court
evidence
•Photograph must be taken–Before any attempts at
preservation
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 57
Transporting Prints• small object: preserve in its
entirety. • large immovable objects
– developed with a powder– “lift” with a broad adhesive tape.– tape placed on properly labeled
card– good background contrast with the
powder
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 58
Digital Imaging• Picture converted into digital
computer file• Help of digital imaging software–Enhanced for the most
accurate and comprehensive analysis
• Compare function–Two images side by side–Allows the examiner to chart
the common features on both images simultaneously
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 59
Fingerprint Patterns
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 60
Taking Fingerprints
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 61
SummarySummary
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 62
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 63
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 64
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PRENTICE HALL ©2007 Pearson Education, Inc. Upper Saddle River, NJ 07458
CRIMINALISTICS An Introduction to Forensic Science, 9/EBy Richard Saferstein 65