characteristics of fingerprints fingerprint 1. history of fingerprinting used in china to seal...
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History of Fingerprinting
Used in China to seal documents for 3,000 years Unclear if it was meant for identification Thumbprint was legal signature
1600s-1800s Ridge patterns found on fingertips Ridge patterns broken into 9 groups
1858 William James Herschel developed system of using
thumbprints to identify individuals collecting pensions First use for criminal investigation
History of Fingerprinting
1882 Gilbert Thompson first person to use
fingerprints in the United States Also used patterns to identify fraud
1883 First human ID system devised Based upon exact body size Assumed body remained the same after age 20 Consisted of 11 measurements including reach,
height, head size, etc. Thrown out around the turn of the century in
favor of fingerprints
History of Fingerprinting
1891 Juan Vucetich is first person to collect
fingerprints and keep them on file First person to solve a murder using
fingerprint evidence Mother killed her two sons – left a bloody
handprint on a door post
History of Fingerprinting
1892 Francis Galton publishes Fingerprints
Cousin of Charles Darwin Setup methods for identification and structure of
fingerprints Believed fingerprints were unique and unchanging Odds that two individuals having the same
fingerprints is 1 in 64 billion Designs system to categorize large numbers of
prints Still in use today
History of Fingerprinting
1896 Edward Henry developed fingerprinting system
to track criminals in England Assigned to Scotland Yard Broke down fingerprints into loops, arches,
whorls, and composites 1902
First use of fingerprints in the US for criminal reasons
NY state prison system starting fingerprinting its criminals
Creates the modern “Ten card”
History of Fingerprinting
1908 All US Armed Services fingerprint their troops
1908 Modern system put into service Uses printers ink and standardized cards
1972 FBI develops first computerized reader of
fingerprints Now has the largest collection in world
1998 AFIS (Automated Fingerprint Identification
System) is born
Automated Fingerprint Identification System
International in use Based on laser scanning Database looks for matching
characteristics between prints on file and suspect Based on “minutae” Looks at “constellations”
Fingerprints as Evidence
Has been tested considerably in court Most recent attempt was in 1999 but
was ruled admissable Issue is that there is no standard for
matching Prints are not matched for 100% accuracy Look to match “constellations” of major
features
Basic Characteristics
No two have ever found to be the same (including twins)
Prints remain unchanged throughout an individuals life
Individually NOT determined by general shape or pattern
Identified by ridge characteristics Point by point matches must be used in court to
establish guilt/innocence Average fingerprint contains 150 individual ridge
characteristics 8 to 16 characteristics is generally considered
adequate for a match in court Even if attempt is made to destroy, some
characteristics always grow back
Structure of Fingerprints
Ridges High points of a print
Grooves Low points of prints
Epidermis Outermost layer of skin Contains print details Outer covering is Non-living
Dermis Inner layer of skin Living tissue Contains sweat and oil glands
Structure of Fingerprints
Papillae Boundary between dermis and epidermis Determines the form and pattern of prints If an injury is deeper then this layer, scarring
will result Pores
Each ridge contains one row Used to channel sweat from sweat ducts to
the skin’s surface Sweat mixes with oils, etc. and is deposited on
any surface the finger touches Often invisible to the human eye and are called
latent fingerprints
Major Print Features
Ridge Ending The end of a normal ridge
Short Ridge A very short ridge
Bifurcation One ridge separated into two
Enclosure A small section of ridge that forms a loop
Ridge Classification Categories
Loops 60% - 65% of population Two types
Whorls 30% - 35% of population Four distinct groups
Arches 5% of population Two distinct groups
Loop Classifications
Loops have three parts Core
Center of the loop Type Line
Ridges that diverge from each other Delta
Closest ridge to the type lines 2 Major types of loops
Radial Loop (Radius = outer arm bone) Loop opens toward the little finger
Ulnar Loop (Ulna = inner arm bone) Loop opens toward thumb
Whorl Classifications
Must have type lines and at least two deltas
Four types Plain
Has at least one ridge that forms a circle or oval An imaginary line drawn between two deltas will
cross the circles Central Pocket Whorl
Has at least one ridge that forms a circle or oval An imaginary line drawn between two deltas will
not cross the circles
Whorl Classification
Four Types (cont.) Double Loop
Has two loops combined into one print Accidental
Print containing two or more different patterns or not covered in other categories
Greater than 2 deltas
Arch Classification
No loops, type lines or deltas Two groups
Plain arches Simplest of all patterns Ridges enter from one side of the print and exit
out the other Ridges tend to rise in the middle of the print “Wavelike” pattern
Tent arches Center rises at sharp angle
The FBI “Ten Card” Classification System
The first classification step in the FBI system
System divides all fingerprints into one of 1,024 categories
Based upon presence/absence of a whorl
The FBI “Ten Card” Classification System
Fingers are paired according to following method below:
R. index R. ring L. thumb L. middle L. littleR. thumb R. middle R. little L. index L. ring
The FBI “Ten Card” Classification System
If a whorl is found on any finger of the first pair, a value of 16 is given ...second pair, value of 8 ...third pair, value of 4 ...fourth pair, value of 2 ...fifth pair, value of 1
Any finger having a loop or arch pattern is given a zero
After values for all ten fingers are found, numerators and denominators are added up for a fractional classification number
Finally, 1/1 is added to the total value for the final classification