Fingerprints The Basics T. Trimpe 2006 http://sciencespot.net

History of Fingerprints

HISTORY 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?

HISTORY 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

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

Bertillon’s System Relied on: Portraite Parlé – Detailed description of the individual Full length and profile photographs Anthropometry – A system of precise body measurements

ANTHROPOMETRY 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 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 GALTON No two prints are identical An individual’s prints remain unchanged from one year to the next

SIR 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

Primary Classification The Henry—FBI Classification Each finger is given a point value right 4 8 16 left 4 2 1 Kendall/Hunt Publishing Company 12

Primary 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 Kendall/Hunt Publishing Company 13

Primary Classification The Henry—FBI Classification Each finger is given a point value right 4 - Loop 8 - Whorl 8 - Arch 16 - Arch 16 - Whorl left 4 - Arch 2 - Loop 2 - Arch 1- Loop 1 - Whorl Kendall/Hunt Publishing Company 14

Primary Classification Assign the number of points for each finger that has a whorl and substitute into the equation: 8 1 10 right right left left left index ring thumb middle little + 1 = right right right left left thumb middle little index ring +1 16 17 That number is your primary classification number 0.59 Kendall/Hunt Publishing Company 15

In 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 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

What are Fingerprints? Friction ridge skin pattern Found on fingers, palms, toes, soles of feet. Composed of ridges (hills) and furrows (valleys) Black = Ridges White = Valleys 19

What are Fingerprints? Develop in early embryonic development. Pattern based on genetics, detail somewhat random Identical twins do not have identical fingerprints 20

FUNDAMENTALS OF FINGERPRINTS FIRST PRINCIPLE: Friction Ridges develop their Unique form in the fetus

FUNDAMENTALS OF FINGERPRINTS SECOND PRINCIPLE: A Fingerprint will remain LARGELY UNCHANGED during an Individual’s Lifetime

FUNDAMENTALS OF FINGERPRINTS THIRD PRINCIPLE: Friction Ridge Patterns and their details are UNIQUE. No Two Fingers have yet been found to possess IDENTICAL RIDGE CHARACTERISTICS (even identical twins!!)

FUNDAMENTALS OF FINGERPRINTS FOURTH PRINCIPLE: FINGERPRINTS CAN BE SYSTEMATICALLY CLASSIFIED by GENERAL RIDGE PATTERNS

Fingerprint Classes There 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. Arch Plain arch Tented arch Loop Radial Loop Ulnar loop Whorl Plain whorl Central pocket whorl Double loop whorl Accidental whorl

60% of people have loops, 35% have whorls, Interesting Info Fingerprint Factoid: 60% of people have loops, 35% have whorls, and 5% have arches Did you know? Dactyloscopy is the study of fingerprint identification. Police investigators are experts in collecting “dactylograms”, otherwise known as fingerprints.

Arches Arches 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. Tented Arches Similar to the plain arch, but has a spike in the center. Spike or “tent” Plain Arch Ridges enter on one side and exit on the other side.

Loops Left Hand Right Hand Loops 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. Ulnar Ulnar Radius Help: “UP RT” Ulnar Pinkie side If Left Hand – Radial Loop If Right Hand - Ulnar Loop Radial Thumb side If Left Hand – Ulnar Loop If Right Hand - Radial Loop Delta X-Ray Imagine: http://www.tooloop.com/wp-content/uploads/2013/12/Radius-Ulna-X-Ray.jpg

Whorls – Part 1 Whorls 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. Central Pocket Whorl Plain Whorl ***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.

Whorls – Part 2 Double Loop Whorl Accidental Whorl Double loop whorls are made up of any two loops combined into one print. Delta 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. Delta Delta Delta Delta Plain Arch

Ridge Ending Dot Island Bifurcation Minutiae, also known as ridge characteristics. They help create unit ridge patterns. Bifurcation Ridge Ending Dot Island 31

Range of 8-16 comparative points 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… Deltas? Zero=Arch One=Loop Two=Whorl 2. Arch? No center spike=Plain Center spike=Tented 3. Loop? Thumb=Radial Pinkie=Ulnar 4. Whorl? Touches Delta Line=Plain No touch Delta Line=Central Pocket Two loops wrapped together=Double Loop Two + patterns fitting other category=Accidental Left Hand… Answer Key: A - Plain Whorl, B – Double Loop Whorl, C – Ulnar Loop, D – Tented Arch, E – Plain Arch Right Hand… Right Hand…. Left Hand….

It’s time to make some prints! Avoid Partial Prints GOOD PRINT Get as much of the top part of your finger as possible!

Directions 1st – 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.