Chapter 4 Fingerprints Fingerprints can not lie but

Chapter 4: Fingerprints “Fingerprints can not lie, but liars can make fingerprints. ” —Unknown

Fingerprints Students will learn: § Why fingerprints are individual evidence. § Why there may be no fingerprint evidence at a crime scene. § How computers have made personal identification easier. Chapter 4 Kendall/Hunt Publishing Company 1

Fingerprints Students will be able to: § § § Chapter 4 Define three basic properties that allow individual identification by fingerprints. Obtain an inked, readable fingerprint for each finger. Recognize the general ridge patterns (loops, whorls, and arches) Identify friction ridge characteristics and compare two fingerprints with at least ten points of identification. Explain the differences among latent, plastic, and visible fingerprints. Develop latent prints (make them visible) using physical and chemical methods. Kendall/Hunt Publishing Company 2

Fundamental Principles of Fingerprints § A fingerprint is an individual characteristic. § Fingerprints will remain unchanged during an individual’s lifetime. § Fingerprints have general characteristic ridge patterns that permit them to be systematically classified. Chapter 4 Kendall/Hunt Publishing Company 3

History of Fingerprints Dactyloscopy is the study of fingerprints. Early Contributions came from: § William Herschel (1877)—required Indians to put their fingerprints on contracts: also used them to identify prisoners Chapter 4 Kendall/Hunt Publishing Company 4

History of Fingerprints Henry Faulds (1880) —claimed that fingerprints did not change over time and that they could be classified for identification: used an ink and transfer method to record prints. Chapter 4 Kendall/Hunt Publishing Company 5

History of Fingerprints LAlphonse Bertillon (1881)—proposed body measurements as a means of identification (anthropometry) Chapter 4 Kendall/Hunt Publishing Company 6

History of Fingerprints § Francis Galton (1891)— developed a classification scheme based on loops, arches and whorls: also, showed that no two prints are alike and that they can not be altered. Chapter 4 Kendall/Hunt Publishing Company 7

History of Fingerprints § Edward Richard Henry (1897)—worked with Galton to institute a numerical classification system which is currently used in most Englishspeaking countries Chapter 4 Kendall/Hunt Publishing Company 8

History of Fingerprints § Juan Vucetich (1901) —developed a similar classification system for Spanish-speaking countries Chapter 4 Kendall/Hunt Publishing Company 9

History of Fingerprints § The Identification Division of the FBI was formed in 1924. § Currently, FBI has 250 million sets of fingerprints records Chapter 4 Kendall/Hunt Publishing Company 10

Anatomy of Fingerprints LThe ridges and grooves of fingerprints are known as friction ridges LUnique to each person LAlso found on palms, feet, and lips LNot genetically controlled, so even identical twins will have different fingerprints Chapter 4 Kendall/Hunt Publishing Company 11

Anatomy of Fingerprints LThe friction ridge on the epidermis is determined by a lower layer known as the papillae LChemically or physically altering the epidermis only causes pain because the original print will soon grow back. LFingerprint residue is made up of salt, complex organic compounds and body oil. Residue of most prints is about 1 microgram (one-millionth of a gram) Chapter 4 Kendall/Hunt Publishing Company 12

Classification of Fingerprints LAll fingerprints can be classified into three basic patterns: LLoops (65% of all fingerprints) LWhorls (20 % of all fingerprints) LArches (least common) Chapter 4 Kendall/Hunt Publishing Company 13

Loop Core Delta Chapter 4 Ridge § A loop must have one or more ridges entering and exiting from the same side. Loops must have one delta (triangular area) and a core § Two Types § Radial —opens toward the thumb § Ulnar —opens toward the “pinky” (more common) § Which type of loop is this, if it is on the right hand? Left hand? (If you do not know which hand left the print, you can not determine type) Kendall/Hunt Publishing Company 14

Whorl Core § Whorls: subdivided into 4 groups: § Types § § Plain Central Pocket Double Loop Accidental § A plain or central pocket whorl has at least one ridge that makes a complete circuit. A double loop is made of two loops. An accidental is a pattern not covered by other categories. Whorls have at least two deltas and a core Chapter 4 Kendall/Hunt Publishing Company Delta 15

Arch An arch is the least common and simplest pattern. Arches have no delta or core. All ridges enter one side and exit the other. Types § Plain § Tented Chapter 4 Plain Arch Kendall/Hunt Publishing Company 16

All Eight Fingerprint Types Prints are from the right hand Whorl http: //viewzone 2. com/fingerprint. html Chapter 4 Kendall/Hunt Publishing Company 17

Primary Classification In the The Henry—FBI Classification (Developed by Edward Henry) each finger is given a point value right Chapter 4 left Kendall/Hunt Publishing Company 18

Primary Classification Assign the number of points for each finger that has a whorl and substitute into the equation (one is added to the numerator and denominator to avoid having zeros in the classification): right index 16 right thumb 16 right left ring thumb 8 4 right middle little 8 4 left middle little 2 1 left index ring 2 1 +1 = +1 That number is your primary classification number Chapter 4 Kendall/Hunt Publishing Company 19

Primary Classification LThe primary classification number is used to narrow a search. LThis method (The Primary Henry-FBI Classification) allows all sets of ten fingerprints to be divided into 1, 024 groups. LThe frequency of loops, whorls and arches present in the general population has been determined. Chapter 4 Kendall/Hunt Publishing Company 20

Frequency of Patterns L Example: About 25% of people have no whorls—so a primary classification of 1/1 is quite common. L The chart below shows the frequency of fingerprint patterns in the general population Loops Chapter 4 Whorls Arches Ulnar Radial Plain Other Plain Tented 60% 5% 20% 10% 4% 1% Kendall/Hunt Publishing Company 21

Ridge Classification LAfter primary classification, scientists must then use the fine structure of ridge characteristics called minutiae to individualize them. Chapter 4 Kendall/Hunt Publishing Company 22

Ridge Characteristics Minutiae —ten different patterns are used § § § § § Ridge ending Short ridge Dot or fragment Bifurcation Double bifurcation Trifurcation Bridge Island Enclosure Spur Chapter 4 Kendall/Hunt Publishing Company 23

Fingerprint Minutiae Chapter 4 Kendall/Hunt Publishing Company 24

Comparison There are no legal requirements in the United States on the number of points. Generally, criminal courts will accept 8 to 12 points of similarity. Chapter 4 Kendall/Hunt Publishing Company 25

Types of Prints LPlastic prints : (aka. indented or molded prints): prints transferred into materials such as fresh paint, putty, soap, wax, gum, envelopes, stamps, even a softened candy bar. http: //martens. ganoksin. com/blogs Chapter 4 Kendall/Hunt Publishing Company / 26

Types of Prints LVisible prints: prints left by a finger that has touched colored material such as blood, paint, ink, grease, chalk, mud, or dust. Chapter 4 http: //hubpages. com/hub/information-on-fingerprints Kendall/Hunt Publishing Company 27

Types of Prints § Latent fingerprints are those that are not visible to the naked eye. These prints consist of the natural secretions of human skin and require development for them to become visible. Chapter 4 Kendall/Hunt Publishing Company 28

Latent Prints § Most secretions come from three glands: § Eccrine —largely water with both inorganic (ammonia, chlorides, metal ions, phosphates) and organic compounds (amino acids, lactic acids, urea, sugars). Most important for fingerprints. § Apocrine —secrete pheromones and other organic materials. § Sebaceous —secrete fatty or greasy substances. Chapter 4 Kendall/Hunt Publishing Company 29

Developing Latent Prints § Developing a print requires substances that interact with secretions that cause the print to stand out against its background. § It may be necessary to attempt more than one technique, done in a particular order so as not to destroy the print. Chapter 4 Kendall/Hunt Publishing Company 30

Developing Latent Prints § Powders —adhere to both water and fatty deposits. They can be used on hard, nonporous surfaces. Choose a color to contrast the background. Prints can then be “lifted” with sticky tape. Chapter 4 Kendall/Hunt Publishing Company 31

Developing Latent Prints LVarious chemical methods can be used to visualize prints on porous surfaces such as paper, styrofoam and leather. LIodine —fumes react with oils and fats to produce a temporary yellow brown reaction. Chapter 4 Kendall/Hunt Publishing Company Iodine print 32

Developing Latent Prints LNinhydrin —reacts with amino acids to produce a purple color. http: //www. forensicscience. net/tools Chapter 4 Kendall/Hunt Publishing Company 33

Developing Latent Prints LSilver nitrate —reacts with salt from sweat to form silver chloride, a material which turns gray when exposed to light. Chapter 4 Kendall/Hunt Publishing Company 34

Super glue fuming §Cyanoacrylate— Cyanoacrylate “super glue” fumes react with water and other fingerprint constituents to form a hard, whitish deposit. It can be used for prints on metals, glass, and plastics. Chapter 4 Kendall/Hunt Publishing Company 35

Order is Important LAlways do the least damaging test first: LIodine fuming LNinhydrin LSilver nitrate—last because it will wash away traces of fatty oils and proteins Chapter 4 Kendall/Hunt Publishing Company 36

Developing Latent Prints § In modern labs, lasers and alternative light sources are used to view latent fingerprints. § These were first used by the FBI in 1978. Since lasers can damage the retina of the eye, special precautions must be taken. Chapter 4 Kendall/Hunt Publishing Company 37

AFIS § The Automated Fingerprint Identification System - a computer system for storing and retrieving fingerprints § Began in the early 1970’s to: § Search large files for a set of prints taken from an individual § Compare a single print, usually a latent print developed from a crime scene Chapter 4 Kendall/Hunt Publishing Company 38

AFIS § By the 1990’s most large jurisdictions had their own problem - a person’s fingerprints may be in one AFIS but not in others Chapter 4 Kendall/Hunt Publishing Company 39

IAFIS § Problems were lessened when the FBI created IAFIS (Integrated Automated Fingerprint Identification System): a national database of all 10 print cards from all over the country. Chapter 4 Kendall/Hunt Publishing Company 40

Other Prints § Ears—shape, length and width § Voice—electronic pulses measured on a spectrograph § Foot—size of foot and toes; friction ridges on the foot § Shoes—can be compared and identified by type of shoe, brand, size, year of purchase, and wear pattern. Chapter 4 Kendall/Hunt Publishing Company 41

Other Prints Palm—friction ridges can be identified and may be used against suspects. Chapter 4 Kendall/Hunt Publishing Company 42

Other Prints Birth footprints can be used as a means of identification of infants. Chapter 4 Kendall/Hunt Publishing Company 43

Other Prints Lips—display several common patterns § § Short vertical lines Short horizontal lines Crosshatching Branching grooves Chapter 4 Kendall/Hunt Publishing Company 44

Other Prints Teeth—bite marks are unique and can be used to identify suspects. These imprints were placed in gum and could be matched to crime scene evidence. Chapter 4 Kendall/Hunt Publishing Company 45

Other Prints The blood vessel patterns in the eye may be unique to individuals. They are used today for various security purposes. Chapter 4 Kendall/Hunt Publishing Company 46

Biometrics § Use of some type of body metrics for the purpose of identification. (The Bertillon system may actually have been the first biometry system. ) § Used today in conjunction with AFIS § Examples include retinal or iris patterns, voice recognition, hand geometry Chapter 4 Kendall/Hunt Publishing Company 47

Biometrics LOther functions for biometrics —can be used to control entry or access to computers or other structures; can identify a person for security purposes; can help prevent identity theft or control social services fraud. Chapter 4 Kendall/Hunt Publishing Company 48

More about Prints For additional information about prints and crime, check out Court TV’s Crime Library www. crimelibrary. com/criminal_mind/forensics/fing erprints/1. html Chapter 4 Kendall/Hunt Publishing Company 49