1. society
2. crime

Notes
Ch. 14 Fingerprints
I. History of Fingerprints
• Police have always looked for a foolproof
method of human identification.
• 1st system: Bertillon 1883 called
anthropometry
A. Early Use of Fingerprints
1. Chinese: ~1000 B.C. used F.P. to sign legal
documents
2. 1880: Fauld and Herschel suggested that
fingerprints are useful for ID criminals
B. Early Classification of Fingerprints
1. Galton, in 1892, published Finger Prints
a. Demonstrated no 2 F.P. are identical
b. Showed individuals F.P. remain
unchanged in life
c. Proposed 3 F.P. categories
1. Loops (~60%)
2. Whorls (~30-35%)
3. Arches (~5-10%)
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.)
C. Adoption of Fingerprints
1. 1901-New York City adopted F.P.
2. 1903-Prison “Twins”
-2 criminals looked and measured identically
-fingerprints were very different
3. 1904-World’s Fair: Police trained by Scotland
Yard
II. Fundamental Principles of F.P.
A. 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
1. I.D. of fingerprints based on Ridge
Characteristics (a.k.a. minutaie)
2. Ridge Characteristics
A. bifurcation
B. ridge ending
C. ridge island
D. enclosure
E. short ridge
F. bridge
G. Crossover
H. Spur (hook)
Let’s practice!
• Take out a pen (blue or black ink) and clear
everything else off your desk.
• Balloon prints
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.
2. Shape of dermal papillae
determines form and pattern of
ridges
• Papillae
are cells that
separate
epidermis
from dermis.
C. Third Principle
• Fingerprints have general ridge patterns that
permit them to be systematically classified
1. General patterns
A. 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
III. Classification of
Fingerprints
A. Fingerprint Vocab
1. Core: center of the fingerprint
2. Delta: triangular area
B. Specific Types of Fingerprints
•
Two Types of ARCHES
Arch-all lines enter and exit from opposite
sides of finger
1. Plain Archrolling hill
2. Tented Archdrastic spike
• 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!!
• 4 Types of Whorls
whorl-2 deltas; at least one ridge line does
not exit finger
1. Plain Whorlline between deltas
intersects circles
2. Central Pocket Loop
Whorl-line btwn deltas
does not intersect full
circles;
Practice
• Plain whorl or central pocket loop whorl?
ANS: Central pocket loop whorl
Practice
• Plain whorl or central pocket loop whorl?
ANS:
Plain
whorl
More Whorls
3. Double loop whorl:
looks like yin yang
4. Accidental whorlcharacterized by 3
deltas; frowny face
More Examples
Accidental Whorls: 2 or more types
of prints
Practice
• Double loop whorl or accidental whorl?
ANS: double loop whorl
Practice
• Double loop whorl or accidental whorl?
ANS: accidental whorl
Let’s practice!
• Please take your Unit 2
classwork paper.
• Date: 9/22/14
• Title: WS: Classification of FP #2
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)
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)
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+ 0 + 4
2
0
0 + 1
3
=
0 + 1
5
• Suspect F.P.
Example #2
Finger
Left
Right
Thumb
Arch
Whorl
Index
Loop
Loop
Middle
Loop
Arch
Ring
Loop
Whorl
Little
Arch
Arch
0 + 8 + 0
16 + 0 + 0
0
0
0 + 1
9
=
0 + 1
17
**Do not reduce fraction: 2/4 stays as 2/4
Practice
Take out Unit 2 Classwork paper.
Date: 9/23/14
Title: FP Code Practice
• Find your own classification code.
• Determine your partner’s classification code.
• Compare your answers.
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
III. 3 Types of Crime Scene Prints
1. Visible-can be seen by naked eye
Ex: prints left in blood, paint, dust,
grease, ink
2. Plastic-occurs when ridge impressions
are left in soft material
Ex: prints left in wax, play-doh, soap,
puddy
3. Latent (Invisible)-not seen by naked
eye; caused by a transfer of oils onto
surface
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
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
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