9e0b440dea5b6e3f5fcfba474fd7e881.ppt
- Количество слайдов: 47
FINGERPRINTS
History of Fingerprints
HISTORY OF FINGERPRINTING l l 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 l l 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 1 st suspect - No match; compared with 2 nd suspect with positive association
HISTORY OF FINGERPRINTING l l l 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 l 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: l Portraite Parlé – Detailed description of the individual l Full length and profile photographs l Anthropometry – A system of precise body measurements
ANTHROPOMETRY l l l 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 - to include height, width of head & length of left foot
FRANCIS GALTON l l l 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 l l No two prints are identical An individual’s prints remain unchanged from one year to the next
SIR EDWARD HENRY l l l 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
In the United States l l l 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 l l l 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
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
FUNDAMENTALS OF FINGERPRINTS MINUTIAE - Ridge Characteristics Define Individuality • • • IDENTITY NUMBER RELATIVE LOCATION COMPARE POINT BY POINT POSSIBLY 150 POINTS ON THE AVERAGE FINGERPRINT
FUNDAMENTALS OF FINGERPRINTS MINUTIAE - Ridge Characteristics Define Individuality HOW MANY POINTS MAKE A MATCH? Depends on experience and knowledge of the examiner Usually 8 to 16
FUNDAMENTALS OF FINGERPRINTS FRICTION SKIN RIDGES Palm Side of Fingers and Thumbs Soles of Feet Provide Firmer Grasp Resistance to Slippage Lines corresponding to Hills (ridges) & Valleys (grooves)
SKIN COMPOSED OF LAYERS OF CELLS EPIDERMIS - OUTER DERMIS - INNER LAYER DERMAL PAPILLAE IN BETWEEN
SKIN RIDGES CONTAIN PORES Openings for ducts from sweat glands Perspiration discharged to surface of skin Transfer is called LATENT FINGERPRINTS
FUNDAMENTALS OF FINGERPRINTS ARCHES 5% LOOPS 60% - 65% WHORLS 30% - 35%
FUNDAMENTALS OF FINGERPRINTS ARCHES - least common of three general patterns • RIDGES ENTER ONE SIDE OF PATTERN AND EXIT ANOTHER • • PLAIN ARCHES - wavelike pattern TENTED ARCHES - sharp spike
FUNDAMENTALS OF FINGERPRINTS • • • LOOPS - most common type Ridges enter one side and exit same side ULNAR LOOP - opens toward little finger RADIAL LOOP - opens toward thumb
FUNDAMENTALS OF FINGERPRINTS LOOPS - • CORE • TYPE LINES • DELTA
FUNDAMENTALS OF FINGERPRINTS WHORLS - FOUR TYPES • • l Plain Central pocket loop Double loop Accidental ALL HAVE TWO DELTAS & TYPE LINES
FINGERPRINT DEVELOPMENT
Types of Fingerprints VISIBLE RIDGES PLACED ON A SURFACE AFTER CONTACT WITH A COLORED MATERIAL (blood, paint, grease, ink)
Types of Fingerprints PLASTIC RIDGES LEFT ON A SOFT MATERIAL (putty, wax, soap, dust)
Types of Fingerprints LATENT HIDDEN OR INVISIBLE TRANSFER OF BODY PERSPIRATION OR OILS MUST BE ENHANCED
Types of Surfaces NON-POROUS GLASS, MIRROR, PLASTIC, PAINTED SURFACES ENHANCE WITH SUPER GLUE and/or POWDER
Types of Surfaces POROUS PAPER, CARDBOARD, CLOTH ENHANCE WITH CHEMICALS
METHODS OF ENHANCEMENT FINGERPRINT POWDERS l l l BLACK (white surfaces) GRAY (dark surfaces) FLUORESCENT (multi-colored surfaces) MAGNETIC (leather or rough plastic) ADHERES TO PERSPIRATION and/or BODY OILS
METHODS OF ENHANCEMENT CHEMICALS IODINE FUMING NINHYDRIN - REACTS WITH PROTEINS PHYSICAL DEVELOPER - SILVER NITRATE BASED - USED WHEN OTHER METHODS UNSUCCESSFUL
METHODS OF ENHANCEMENT CHEMICALS SUPER GLUE FUMING - • • CYANOACRYLATE ESTER NON-POROUS SURFACES CREATE FUMES WITH HEAT PORTABLE WAND AVAILABLE
METHODS OF ENHANCEMENT FLUORESENCE l PERSPIRATION CONTAINS COMPONENTS THAT FLUORESCE WHEN ILLUMINATED WITH LASER LIGHT l HIGHLY SENSITIVE ALTERNATE LIGHT SOURCE l l • • • QUARTZ HALOGEN ZENON ARC INDIUM ARC DOES NOT INTERFERE WITH DNA TESTING
PRESERVATION AND COMPARISON OF FINGERPRINTS
PRESERVATION OF ENHANCED PRINTS PHOTOGRAPHY • 1: 1 SCALE LIFTING • • TAPE HINGED LIFTER
PRESERVATION OF ENHANCED PRINTS DIGITAL IMAGING • • SCANNER • • • REMOVE BACKGROUND COLORS DIGITAL CAMERA VIDEO CAMERA ENHANCE WITH FILTERS, CONTRAST OR BRIGHTNESS SCALING / RESIZING TOOLS SIDE-BY-SIDE COMPARISON
AFIS Automated Fingerprint Identification System
AFIS Automatic Scanning Devices Convert Fingerprint Image into Digital Minutiae • RIDGE ENDINGS • BIFURCATIONS
AFIS Types of Databases • Arrest Prints (KNOWNS) • Forensic Prints (CRIME SCENE)
AFIS SEARCH ALGORITHM DETERMINES DEGREE OF CORRELATION BETWEEN THE QUESTIONED AND KNOWN PRINTS
AFIS l THOUSANDS OF COMPARISONS PER SECOND l ALL SELECTED PRINTS VERIFIED BY TRAINED EXAMINER l STANDARDS ENABLE AGENCIES TO EASILY EXCHANGE DATA
FINGERPRINT EXAMINER l l 4 YEAR DEGREE 2+ YEARS TRAINING CERTIFICATION PROGRAM • Written Test • Proficiency Test • Continuing Education International Association for Identification (IAI)