CHARACTERISTICS OF FINGERPRINTS Fingerprint 1. History of Fingerprinting Used in China to seal documents for 3,000 years Unclear if it was meant for

CHARACTERISTICS OF FINGERPRINTS

Fingerprint 1

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


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


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


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


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”


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”

AFIS

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

Basic Skin Structure

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

Loop Fingerprint

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

Whorl Fingerprint

Whorl Fingerprint

An example of an accidental whorl. Note the presence of three 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

Arch Fingerprint

Fingerprint Analysis Worksheet






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


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


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

Documents

CHARACTERISTICS OF FINGERPRINTS Fingerprint 1. History of Fingerprinting Used in China to seal documents for 3,000 years Unclear if it was meant for