September 9 2014 What are Fingerprints Does everyone have a unique fingerprint How why and when do fingerprints develop Watch this What are Fingerprints Does everyone have a unique fingerprint ID: 283818
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Slide1
FingerPrints
September 9, 2014Slide2
What are Fingerprints?
Does everyone have a unique fingerprint?
How, why, and when do fingerprints develop?
Watch this!Slide3
What are Fingerprints?
Does everyone have a unique fingerprint?
Yes – even identical twins have different
fingerprints.
How, why, and when do fingerprints develop?
Fingerprints are unique b/c they are influenced by minute details of the womb environment (e.g. flow of amniotic fluid around hand)
Fingerprints help us hold things
Fingerprints develop by 24 weeks gestationSlide4
What are Fingerprints?
Can you alter your fingerprints?
Watch this!Slide5
What are Fingerprints?
Can you alter your fingerprints?
No, you can form scar tissue over parts of your
fingers, but usually enough marks remain for
identification.
Slide6
What are Fingerprints?
Can you alter your fingerprints?
John Dillinger (aka Public Enemy Number One) underwent plastic surgery and used acid to try to remove his fingerprints. After he was killed, however, he was fingerprinted in the morgue, and the ‘altered’ fingerprints still matched the originals.Slide7
History of Fingerprinting
Fingerprints have served as unique signatures since prehistoric timesEarly potters & scribes left fingerprints in clay
Businessmen in China’s
T’ang
dynasty (8
th
century AD) used fingerprints on business contractsSlide8
History of Fingerprinting
Scientific study of fingerprints1891 Francis Galton
classified fingerprints using loops, whirls, and arches
demonstrated that fingerprints are unique and unchangingSlide9
History of Fingerprinting
1892 First reported use of fingerprints to solve a crime, in Argentina.
1899 Sir Edward Henry developed a way of classifying fingerprints so that investigators could quickly narrow down possible matches.
“Henry system” of classification
Used until computer systems developed
1910 Thomas Jennings is first person in US convicted based on fingerprint evidenceSlide10
AFIS
Automated Fingerprint Identification SystemUsed since 1960s S
cans, encodes, and searches fingerprint images
After match(
es
) found, a fingerprint expert evaluates the matches
Problem with current system: not all databases linked Slide11
Finger Print Patterns
What ARE fingerprints?The fingers, toes, palms of hands, and soles of feet have
friction ridge skin
made of
ridges
(raised areas)
and
furrows
(valleys).
Are ridges dark or light?
Why?Slide12
Finger Print Patterns
What are the 3 basic patterns?Slide13
Finger Print Patterns
What are the 3 basic patterns?Slide14
Finger Print Patterns - Arches
Arches enter from one side of the finger, rise in the middle, and exit the other side
Least common pattern (~5%)
Can be plain (low rise) or tented (high rise)
Plain arch
Tented archSlide15
Finger Print Patterns - Loops
Loops enter from one side, rise, and go back out the same side
Most common pattern (~65%)
Have a
core
(the
center of the pattern)
and a
delta
(a triangular area)
green arrow = core
red arrow = deltaSlide16
Finger Print Patterns - Loops
Loops enter from one side, rise, and go back out the same side
Most common pattern (~65%)
Have a
core
(the
center of the pattern)
and a
delta
(a triangular area)
green arrow = core
red arrow = delta
NOTICE! Only 1 or more of the ridges must enter and exit from the same side to be a loop!Slide17
Finger Print Patterns - Loops
Radial loops
open towards the radius of the arm (i.e. towards the thumb).
Ulnar loops
open towards the ulna of the arm (i.e. towards the pinky)
Is this a radial loop or an ulnar loop?Slide18
Finger Print Patterns - Loops
Radial loops
open towards the radius of the arm (i.e. towards the thumb).
Ulnar loops
open towards the ulna of the arm (i.e. towards the pinky)
Is this a radial loop or an ulnar loop?
You can’t tell without knowing which hand it came from!Slide19
Finger Print Patterns - Loops
Radial loops
open towards the radius of the arm (i.e. towards the thumb).
Ulnar loops
open towards the ulna of the arm (i.e. towards the pinky)
If it came from the right hand …Slide20
Finger Print Patterns - Loops
Radial loops
open towards the radius of the arm (i.e. towards the thumb).
Ulnar loops
open towards the ulna of the arm (i.e. towards the pinky)
If it came from the right hand …
Radial!Slide21
Finger Print Patterns - Whorls
Whorls look like “whirlpools”
Have a core and two or more deltasSlide22
Finger Print Patterns - Whorls
Plain whorls
are spirals or concentric circlesSlide23
Finger Print Patterns - Whorls
Plain whorls
are spirals or concentric circles
C
entral pocket loop whorls
look like a loop with a whirl in the middleSlide24
Finger Print Patterns - Whorls
Plain whorls
are spirals or concentric circles
C
entral pocket loop whorls
look like a loop with a whirl in the middle
Double loop whirls
have two loops that collide to
make an “S” shapeSlide25
Finger Print Patterns - Whorls
Plain whorls
are spirals or concentric circles
C
entral pocket loop whorls
look like a loop with a whirl in the middle
Double loop whirls
have two loops that collide to
make an “S” shape
Accidental whorls
are irregularSlide26
Identify the Pattern!
Fingerprint taken from right hand.Hold up your fingers to show the answer:
Plain arch
Tented arch
Radial loop
Ulnar loop
Central pocket loopSlide27
Identify the Pattern!
Fingerprint taken from right hand.Hold up your fingers to show the answer:
Plain arch
Tented arch
Radial loop
Ulnar loop
Central pocket loopSlide28
Identify the Pattern!
Fingerprint taken from right hand.Hold up your fingers to show the answer:
Plain arch
Tented arch
Radial loop
Ulnar loop
Central pocket loopSlide29
Identify the Pattern!
Fingerprint taken from right hand.Hold up your fingers to show the answer:
Plain arch
Tented arch
Radial loop
Ulnar loop
Central pocket loopSlide30
Identify the Pattern!
Fingerprint taken from right hand.Hold up your fingers to show the answer:
Plain whorl
Central pocket loop
Double loop whorl
Accidental loop whorl
Radial loopSlide31
Identify the Pattern!
Fingerprint taken from right hand.Hold up your fingers to show the answer:
Plain whorl
Central pocket loop
Double loop whorl
Accidental loop whorl
Radial loopSlide32
Identify the Pattern!
Fingerprint taken from right hand.Hold up your fingers to show the answer:
Plain whorl
Central pocket loop
Double loop whorl
Accidental loop whorl
Radial loopSlide33
Identify the Pattern!
Fingerprint taken from right hand.Hold up your fingers to show the answer:
Plain whorl
Central pocket loop
Double loop whorl
Accidental loop whorl
Radial loopSlide34
Identify the Pattern!
You Do:
Make a table of the fingerprints on the figure 12 handout. Identify the overall pattern of each print. Then, see if any prints match. Some will have multiple matches, others will have none.
Letter
Pattern
Matches