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The Basics Fingerprint s T. Trimpe 2006 http://sciencespot.net

The Basics Fingerprints T. Trimpe 2006

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The Basics

Fingerprints

T. Trimpe 2006 http://sciencespot.net

History of FingerprintsHistory of Fingerprints

HISTORY OF FINGERPRINTINGHISTORY OF FINGERPRINTING

Chinese used fingerprints to sign legal documents as far back as three thousand years ago

William Herschel, an English civil servant (India), required natives to sign contracts with an imprint of their right hand – Hindu custom?

Chinese used fingerprints to sign legal documents as far back as three thousand years ago

William Herschel, an English civil servant (India), required natives to sign contracts with an imprint of their right hand – Hindu custom?

HISTORY OF FINGERPRINTINGHISTORY OF FINGERPRINTING

In 1880, Scottish physician, Henry Fauld wrote that skin ridge patterns could be important in identification work

A thief left his fingerprint on a whitewashed wall – compared with 1st suspect - No match; compared with 2nd suspect with positive association

In 1880, Scottish physician, Henry Fauld wrote that skin ridge patterns could be important in identification work

A thief left his fingerprint on a whitewashed wall – compared with 1st suspect - No match; compared with 2nd suspect with positive association

HISTORY OF FINGERPRINTINGHISTORY OF FINGERPRINTING

Fauld offered to set up a system of fingerprints at Scotland Yard (at his own expense)

Rejected in favor of the Bertillon System

This decision reversed less than two decades later

HISTORY OF FINGERPRINTINGHISTORY OF FINGERPRINTING

The first systematic attempt at personal identification was devised and introduced by the French police expert, Alphonse Bertillon, in 1883.

The first systematic attempt at personal identification was devised and introduced by the French police expert, Alphonse Bertillon, in 1883.

Bertillon’s SystemBertillon’s System

Relied on: Portraite Parlé – Detailed description of

the individual Full length and profile photographs Anthropometry – A system of precise

body measurements

ANTHROPOMETRYANTHROPOMETRY A method of identification Based upon the premise that the

dimensions of the human skeletal system remained fixed from age 20 until death

Eleven (11) measurements taken include height, width of head & length of left foot

FRANCIS GALTONFRANCIS GALTON In 1892, published the classic work

Finger Prints In this book he discussed the anatomy

of fingerprints and suggested methods for recording them

Proposed three pattern types: loops, whorls and arches

FRANCIS GALTONFRANCIS GALTON

No two prints are identical An individual’s prints remain

unchanged from one year to the next

SIR EDWARD HENRYSIR EDWARD HENRY

Englishman In 1897, proposed another

classification system which is still in use today

Most English-speaking countries use some version of Henry’s classification system

Chapter 4Kendall/Hunt Publishing Company

12

Primary ClassificationPrimary ClassificationThe Henry—FBI ClassificationEach finger is given a point value

right

4

88

16

16

left

4

2

21

1

Chapter 4Kendall/Hunt Publishing Company

13

Primary ClassificationPrimary Classification

Assign the number of points for each finger that has a whorl and substitute into the equation; loops & arches are assigned zero.right right left left left index ring thumb middle little + 1

right right right left left thumb middle little index ring +1

That number is your primary classification number

=

Chapter 4Kendall/Hunt Publishing Company

14

Primary ClassificationPrimary ClassificationThe Henry—FBI ClassificationEach finger is given a point value

right

4 - Loop

8 - Whorl8 - Arch

16 - Arch

16 - Whorl

left

4 - Arch

2 - Loop

2 - Arch1- Loop

1 - Whorl

Chapter 4Kendall/Hunt Publishing Company

15

Primary ClassificationPrimary Classification

Assign the number of points for each finger that has a whorl and substitute into the equation:right right left left left index ring thumb middle little + 1

right right right left left thumb middle little index ring +1

That number is your primary classification number

=

18

16

10

0.59

17

In the United StatesIn the United States

1901 – First systematic use of fingerprints adopted by the New York Civil Service Commission

1904 – American police received training in fingerprint techniques from Scotland Yards representatives

1924 – Fingerprint records from the Bureau of Investigation and Leavenworth merged to form records for the new FBI

Admissibility of FingerprintsAdmissibility of Fingerprints Challenged in the case of United States v. Byron C.

Mitchell Argued under Daubert guidelines that fingerprints

were not unique Judge upheld admissibility and ruled: 1. Human friction ridges are unique and permanent 2. Human friction ridge skin arrangements are unique and permanent

PHYSIOLOGY OF FINGERPRINTS

PHYSIOLOGY OF FINGERPRINTS

19

Friction ridge skin pattern

Found on fingers, palms, toes, soles of feet.

Composed of ridges (hills) and furrows (valleys)

Black = RidgesWhite = Valleys

What are Fingerprints?

20

Develop in early embryonic development.

Pattern based on genetics, detail somewhat random

Identical twins do not have identical fingerprints

What are Fingerprints?

FUNDAMENTALS OF FINGERPRINTS FUNDAMENTALS OF FINGERPRINTS

FIRST PRINCIPLE:

Friction Ridges develop their Unique form in the fetus

FIRST PRINCIPLE:

Friction Ridges develop their Unique form in the fetus

FUNDAMENTALS OF FINGERPRINTS FUNDAMENTALS OF FINGERPRINTS

SECOND PRINCIPLE:

A Fingerprint will remain

LARGELY UNCHANGED

during an

Individual’s Lifetime

SECOND PRINCIPLE:

A Fingerprint will remain

LARGELY UNCHANGED

during an

Individual’s Lifetime

FUNDAMENTALS OF FINGERPRINTS FUNDAMENTALS OF FINGERPRINTS

THIRD PRINCIPLE:

Friction Ridge Patterns and their details are UNIQUE.

No Two Fingers have yet beenfound to possess IDENTICAL RIDGE CHARACTERISTICS (even identical

twins!!)

THIRD PRINCIPLE:

Friction Ridge Patterns and their details are UNIQUE.

No Two Fingers have yet beenfound to possess IDENTICAL RIDGE CHARACTERISTICS (even identical

twins!!)

FUNDAMENTALS OF FINGERPRINTS FUNDAMENTALS OF FINGERPRINTS

FOURTH PRINCIPLE:

FINGERPRINTS CAN BE

SYSTEMATICALLY CLASSIFIED by

GENERAL RIDGE PATTERNS

FOURTH PRINCIPLE:

FINGERPRINTS CAN BE

SYSTEMATICALLY CLASSIFIED by

GENERAL RIDGE PATTERNS

Fingerprint ClassesThere are 3 specific classes for all fingerprints based upon their visual pattern: arches, loops, and whorls.

Each group is divided into smaller groups as seen in the lists below.

ArchPlain arch

Tented arch

LoopRadial LoopUlnar loop

WhorlPlain whorl

Central pocket whorlDouble loop whorlAccidental whorl

Interesting Info

Did you know?Dactyloscopy is the study of fingerprint identification.

Police investigators are experts in collecting “dactylograms”, otherwise known as fingerprints.

Fingerprint Factoid: 60% of people have loops, 35% have whorls,

and 5% have arches

ArchesArches are the simplest type of fingerprints that are formed by ridges that enter on one side of the print and exit on the other. No deltas are present.

Plain ArchRidges enter on one

side and exit on the other side.

Tented Arches Similar to the plain arch,

but has a spike in the center.

Spike or “tent”

LoopsLoops must have one delta and one or more ridges that enter and leave on the same side. These patterns are named for their positions related to the radius and ulna bones, i.e. the bone that the loop opening is facing towards.

Delta

If Left Hand – Radial LoopIf Right Hand - Ulnar Loop

If Left Hand – Ulnar Loop If Right Hand - Radial Loop

X-Ray Imagine: http://www.tooloop.com/wp-content/uploads/2013/12/Radius-Ulna-X-Ray.jpg

Left Hand Right Hand

UlnarUlnar

Radius

Help: “UP RT” Ulnar Pinkie sideRadial Thumb side

Whorls – Part 1Whorls have at least one ridge that makes (or tends to make) a complete circuit. They also have at least two deltas. If a print has more than two deltas, it is most likely an accidental.

***Draw a line between the two deltas in the plain and central pocket whorls. If some of the curved ridges touch the line, it is a plain whorl. If none of the center core touches the line, it is a central pocket whorl.

Plain Whorl

Central Pocket Whorl

Whorls – Part 2

Accidental Whorl

Accidental whorls contain two or more patterns (not including the plain arch), or does not clearly fall under any of the other categories.

Double Loop Whorl

Double loop whorls are made up of any two loops combined into one print.

Delta

Delta

Delta

Delta

Delta DeltaPlain Arch

31

Minutiae, also known as ridge characteristics.

They help create unit ridge patterns.

Dot

Bifurcation

Island

Ridge Ending

How many ridge comparisons are necessary to identify two fingerprints as the same?

Range of 8-16 comparative points

Identify each fingerprint pattern.

Right Hand…

Left Hand…

Left Hand….

Right Hand…

Right Hand….

1. Deltas? Zero=Arch One=Loop

Two=Whorl2. Arch? No center spike=Plain Center spike=Tented3. Loop? Thumb=Radial Pinkie=Ulnar4. Whorl? Touches Delta Line=Plain No touch Delta Line=Central Pocket Two loops wrapped together=Double Loop Two + patterns fitting other category=Accidental

It’s time to makesome prints!

Avoid Partial Prints

GOOD PRINTGet as much of the top part of your finger as possible!

Directions1st – Roll the “pad” portion of your thumb over the ink pad from the left side of your thumb to the right. You do not have to push down really hard!

2nd – Roll the “pad” portion of your thumb from the left side of your thumb to the right in the correct box on your paper to make a thumbprint.

3rd – Continue this process to make a fingerprint of all ten fingers on the “My Prints” worksheet.

4th – Use your notes and a magnifying lens to help you figure out what type of pattern is found in each of your fingerprints. Label each one with the pattern’s name.