Chapter 4: Fingerprints “Fingerprints can not lie, but liars can make fingerprints.” —Unknown SFS2. Students will use various scientific techniques to analyze physical and trace evidence. a.Identify and utilize appropriate techniques used to lift and evaluate readable, latent, plastic and visible fingerprints. EQ: How do we lift and evaluate readable latent, plastic, and visible fingerprints?

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

Chapter 4 Kendall/Hunt Publishing Company 2 Students will be able to:  Define the 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. Fingerprints

Chapter 4 Kendall/Hunt Publishing Company 3 Fingerprints Recording Prints  rolling inked prints  primary identification number Lifting Prints  Black, white and fluorescent powder  Chemicals—ninhydrin, iodine, silver nitrate, cyanoacrylate Other Types of Prints  Palm, lip, teeth, eye, ear, voice, shoe and footprints

Chapter 4 Kendall/Hunt Publishing Company 4 Dactyloscopy The study of fingerprints Historically  William Herschel—required Indians to put their fingerprints on contracts, and also as a means of identifying prisoners  Henry Faulds—claimed that fingerprints did not change over time and that they could be classified for identification  Alphonse Bertillon—proposed body measurements as a means of identification; termed anthropometry  Francis Galton—developed a primary classification scheme based on loops, arches and whorls.  Edward Richard Henry—in collaboration with Galton instituted a numerical classification system  Juan Vucetich—developed a fingerprint classification based on Galton’s that is used in Spanish-speaking countries

Chapter 4 Kendall/Hunt Publishing Company 5 Fundamental Principles of Fingerprints  A fingerprint is an individual characteristic.  Fingerprints have general characteristic ridge patterns that permit them to be systematically classified.

Chapter 4 Kendall/Hunt Publishing Company 6 Can You Believe It?  Identical twins have the same DNA configuration but they do not have identical friction ridge configuration  Friction ridges develop on the fetus in their definitive form before birth.  A fingerprint will remain unchanged during an individual’s lifetime.

Chapter 4  Friction ridges are in their definitive form on the fetus before birth.  Once this blueprint has been established, in the stratum basale (generating layer) of the epidermis it does not change except for:  Injury,  Disease or  Decomposition after death. This is part of the dermal papillae layer

Chapter 4 Kendall/Hunt Publishing Company 8 Ridge Characteristics Minutiae—characteristics of ridge patterns  Ridge ending  Short ridge  Dot or fragment  Bifurcation  Double bifurcation  Trifurcation  Bridge  Island  Enclosure  Spur

Chapter 4 Kendall/Hunt Publishing Company 9 Fingerprint Minutiae

Chapter 4 Kendall/Hunt Publishing Company 10 Fingerprint Classification

Chapter 4 Kendall/Hunt Publishing Company 11 Arch An arch has friction ridges that enter on one side of the finger and cross to the other side while rising upward in the middle. They do NOT have type lines, deltas, or cores. Types  Plain  Tented

Chapter 4 Kendall/Hunt Publishing Company 12 Arch These are the least common and simplest of the patterns.

Chapter 4 Kendall/Hunt Publishing Company 13 Fingerprint Classification

Chapter 4 Kendall/Hunt Publishing Company 14 Loop  A loop must have one or more ridges entering and exiting from the same side. Loops must have one delta.  Types  Radial—opens toward the thumb  Ulnar—opens toward the “pinky” (little finger)  Which type of loop is this, if it is on the right hand? Left hand?

Chapter 4 Kendall/Hunt Publishing Company 15 Loop  Without knowing which hand made the print, you can’t tell if it’s radial or ulnar.  Ulnar loops are more common, however.  About 65% of all fingerprints have loops.  Loops have a core near the center of the pattern.

Chapter 4 Kendall/Hunt Publishing Company 16 Fingerprint Classification

Chapter 4 Kendall/Hunt Publishing Company 17 Whorl  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.  Types  Plain  Central Pocket  Double Loop  Accidental

Chapter 4 Kendall/Hunt Publishing Company 18 Whorl  About 20% of fingerprints have plain whorls.  Composites (a mixture of 2 or more basic patterns) and accidentals (prints too irregular to fall into any other group) make up about 10% of all fingerprints.

Chapter 4 Whorl 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

Chapter 4 Kendall/Hunt Publishing Company 20 Fingerprint Classification

Chapter 4 Kendall/Hunt Publishing Company 21 Primary Classification The Henry—FBI Classification Each finger is given a point value rightleft

Chapter 4 Kendall/Hunt Publishing Company 22 Primary Classification Having a primary classification allows all sets of 10 fingerprints in the world to be divided into just 1,024 groups. rightleft

Chapter 4 Kendall/Hunt Publishing Company 23 Primary 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 =

Chapter 4 Kendall/Hunt Publishing Company 24 Primary Classification If you have your books, look at page 54. Calculate your primary Henry-FBI classification number. right right left left left index ring thumb middle little + 1 right right right left left thumb middle little index ring +1 How many people in class have the same number? =

Chapter 4 Kendall/Hunt Publishing Company 25 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. Why might this present a problem in criminal court?

Chapter 4 Kendall/Hunt Publishing Company 26 Latent 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.  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 27 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.  Powders—adhere to both water and fatty deposits. Choose a color to contrast the background.  Iodine—fumes react with oils and fats to produce a temporary yellow brown reaction.

Chapter 4 Kendall/Hunt Publishing Company 28 Using Powder on Latent Prints  Brush the surface lightly with powder  Twist brush gently to remove excess powder  Observe printed area  Use clear tape to lift print and stick it to a card cataloguing location of print and time collected  Note that we will use transparency film to simplify comparison

Chapter 4 Kendall/Hunt Publishing Company 29 Developing Latent Prints  Ninhydrin—reacts with amino acids to produce a purple color.  Silver nitrate—reacts with chloride to form silver chloride, a material which turns gray when exposed to light.  Cyanoacrylate—“super glue” fumes react with water and other fingerprint constituents to form a hard, whitish deposit. In modern labs and criminal investigations, lasers and alternative light sources are used to view latent fingerprints. These were first used by the FBI in Since lasers can damage the retina of the eye, special precautions must be taken.

Chapter 4 Kendall/Hunt Publishing Company 30 Iodine Fingerprint

Chapter 4 Kendall/Hunt Publishing Company 31 Ninhydrin Fingerprint

Chapter 4 Kendall/Hunt Publishing Company 32 Using Cyanoacrylate on Latent Prints  Hang material to be printed with wire in a closable container as fumes are toxic  Heat small amount of glue on light bulb  Allow fumes to clear  Observe prints  Collect as usual  Compare using overhead projector to suspects

Chapter 4 Kendall/Hunt Publishing Company 33 Cyanoacrylate Fingerprints

Chapter 4 Kendall/Hunt Publishing Company 34 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 35 Other Prints Palm—friction ridges can be identified and may be used against suspects.

Chapter 4 Kendall/Hunt Publishing Company 36 Other Prints Footprints are taken at birth as a means of identification of infants.

Chapter 4 Kendall/Hunt Publishing Company 37 Other Prints Lips—display several common patterns  Short vertical lines  Short horizontal lines  Crosshatching  Branching grooves

Chapter 4 Kendall/Hunt Publishing Company 38 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 39 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 40 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  By the 1990’s most large jurisdictions had their own system in place. The problem - a person’s fingerprints may be in one AFIS but not in others  IAFIS—the FBI’s Integrated Automated Fingerprint Identification system which is a national database of all 10-print cards from all over the country

Chapter 4 Kendall/Hunt Publishing Company 41 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  Other 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 42 More about Prints For additional information about prints and crime, check out Court TV’s Crime Library gerprints/1.html