FINGERPRINTS CHAP 14 http investigation discovery com videotopics forensics videos inside-the-csi-labfingerprints htm

FINGERPRINTS CHAP. 14 http: //investigation. discovery. com/videotopics/forensics/videos/inside-the-csi-labfingerprints. htm

History of Fingerprinting o o o 1883 Bertillon System Portrait Parle- verbal eyewitness description, physical characteristics, dress Photographs Anthropometry- skeleton does not change after 20 y. o. , 11 body measurements (height, reach, head width, left foot length) Used for ~ 20 years

History of Fingerprinting o o o Chinese used fingerprints to sign legal documents 3000 years ago 1800’s William Herschel required Indian natives to “sign” contracts with hand imprint 1880 Henry Fauld published the importance of fingerprints for identification (thief confesses when fingerprints compared)

History of Fingerprinting o o o o 1892 Francis Galton publishes Finger Prints Anatomy of FP Methods for identifying and recording Three patterns (loops, arches, whorls) No two prints alike *(calculations 64 billion) FP stay the same British government adopts system as supplement to the Bertillon system

History of Fingerprinting o o 1891 Dr. Juan Vucetich devises workable classification system 1897 Sir Edward Henry’s classification system adopted by Scotland Yard in 1901 Similar version used in United States 1903 Fingerprints distinguished prisoners with same Bertillion measurements (Will West/ William West)

History of Fingerprinting- US o o o 1901 New York City Civil Service Commission first official system in US (civil service applications) 1904 Scotland Yard reps train police officers in FP identification at St. Louis World’s Fair 1924 FBI merges records (Bureau of Investigation and Leavenworth) WWI FP’s used throughout Europe 1999 US vs. Byron C. Mitchell- FP admissibility upheld- “human friction ridges and human friction ridge skin arrangements are unique and permanent”

Fundamental Principles of Fingerprints Three Principles o o o First principle: A fingerprint is an individual characteristic Second principle: A fingerprint will remain unchanged during an individual’s lifetime Third principle: Fingerprints have general ridge patterns that permit them to be systematically classified

First principle: A fingerprint is an individual characteristic o o o No two fingers have yet been found to possess identical ridge characteristics Individuality determined by minutiae/ridge characteristics Individuality-Identity, number and location Ridge endings, bifurcations, enclosures, islands, ridge crossing, short ridge ~150 ridge characteristics per print

First Principle- Judicial Proceeding o o o o FP comparison- Identical characteristics in same location Point-by-point comparison by expert Comparison charts (pg. 409) Usually partials at scene 1973 International Association for Identification- “no valid basis exists for requiring a predetermined minimum number of friction ridge characters which must be present to establish positive identification Usually 8 -16 (~12) Final determination based on experience and knowledge

Fingerprint Comparison

Second principle: A fingerprint will remain unchanged during an individual's lifetime o o Friction Skin provide for firmer grasp and resistance to slippage on the fingers and thumb (palms, soles) Ridges (hills) and Grooves (valleys) Determined by dermal papillae Formed during fetal development

Second Principle o o o Sweat gland pores in ridges Perspiration and oils (from hairy parts of body) transferred to surface leaving fingerprint Can’t change but maybe obscure Scarring down to dermis John Dillinger tried to obliterate prints with acid (pg. 412) http: //investigation. discovery. com/videos/ialmost-got-away-with-it-a-man-withoutfingerprints. html

Third Principle: Fingerprints have general ridge patterns that permit them to be systematically classified o Three classes: Loops, whorls, arches

Fingerprint Patterns- LOOP o o o Most common, 60 -65% Ridge lines enter from one side of pattern, curve around and exit from same side Radial or Ulnar Loop Two Type Lines One Delta Core (“center”)

LOOP

Fingerprint Patterns- Whorl (4) o o o 30 -35% Ridge patterns are rounded or circular Type Lines At least two deltas Plain, Central Pocket Loop, Double loop, Accidental

WHORL o Plain Whorl, Central Pocket At least one ridge makes a complete circle (spiral, oval) Plain- Line between 2 deltas touches circle Central Pocket- Line does not touch circle

o Double Loop- Two loops o Accidental- Combination of patterns

Fingerprint Patterns- Arch o o Least Common (~5%) Plain Arches, Tented Arches Ridge lines enter from one side, rise to center (sharp rise in tented) and exit other side No type lines, deltas or cores

ARCHES o Plain Arch o Tented Arch

Classification of Fingerprints o o o FBI System- Primary Classification- 1 st step Based on Henry’s Ten finger system All cards divided into 1, 024 Groups Need full set of prints Doesn’t identify, narrows down

Primary Classification o o o o Fingers paired up RI RR LT LM LL RT RM RL LI LR Whorl pattern on 1 st pair-16 2 nd pair = 8 3 rd pair = 4 4 th pair = 2 5 th pair = 1 Arch or loop = 0

Primary Classification o o q Values totaled and 1 added to both numerator and denominator Example: (RI and RM are whorls) 16 + 0 + 0 + 1 17 0+ 8+0+0+0+1 9 ~ 25% are in 1/1 category (all fingers are loops or arches)

Automated Fingerprint Identification Systems (AFIS) o o o Automatic scanning devices convert FP image to digital minutiae showing ridge endings and bifurcation Stores and retrieves FP record Thousands of comparisons in seconds Produces list of file prints w/ closest correlation National Institute of Standards and Technology exchange of data between AFIS systems Final verification by FP expert

AFIS

Kinds of Fingerprints o o o Visible- are visible!!, print left by material transferred from finger to surface (blood, ink, paint, grease) Plastic (physical)- impression left on soft surface (putty, soap, wax, caulking, dust) Latent- not visible to naked eye, perspiration and/or oil transferred to surface

Detecting Fingerprints o o o Depends on surface: Nonabsorbent Surfaces- hard, solid (Exglass, mirror, tile, painted wood) Porous Surfaces- soft, low density (paper, cardboard, cloth)

Detecting Fingerprints- RUVIS o o Reflected Ultraviolet Imaging System Locate prints on nonabsorbent surfaces No chemicals or powders UV light print reflected back UV converted to visible light by image intensifier

RUVIS

Latent Print on Duct Tape

Latent Print on Painted Wall

Nonabsorbent Surfaces-Powders o o o Apply w/ camel’s hair or fiberglass brush Aluminum dust (dark-colored surfaces) Black carbon or charcoal (light-colored) Magnetic-sensitive powders (textured) applied with Magna Brush Fluorescent powders visible w/ UV lightprovide for obvious contrast

Powders

Nonporous Surfaces- Super Glue o o o Cyanoacrylate Fumigation Metals, leather, electrical tape, plastic bags Textured surfaces Chamber Produces white-appearing print

Super Glue Fumigation

Porous Surfaces- Chemical Treatments o o o Iodine Fumigation- temporary, must photograph, iodine crystals sublimate to vapor Iodine + Na or Oils = Print (brown) Fix w/starch solution (blue)- visible for weeks/ months Ninhydrin- reacts w/amino acids (protein) in sweat, aerosol spray, turns purple-blue color, 1 -48 hours Physical Developer- silver nitrate based liquid, wet dry articles, washes away proteins

Iodine Fumigation

Ninhydrin

Physical Developer

Laser o o Latent prints fluoresce (absorbs and reemits light in longer wavelengths) when exposed to laser light (argon ion) Chemicals induce fluorescence and increase sensitivity of detection. Zn. Cl after ninhydrin Rhodamine 6 G after Super Glue

ALS o o o Alternate Light Source – High Intensity Quartz halogen, xenon arc, indium arc Focused through fiber optic cable Passed through filter to select wavelength Portable As effective and cheaper than laser

New Chemical Treatments o DFO ( 1, 8 -diazafluoren-9 -one)- 2. 5 times more effective than ninhydrin, porous surfaces, ALS o RAM, RAY, MRM 10 (Dye Combinations) w/Super glue cause fluorescence

Lifting and Preserving Fingerprints o o o Photograph (1: 1) and overall Transport evidence to lab, if possible Preserve DNA Powders lift w/adhesive tape, lifting cards Digital Imaging- picture converted to digital file composed of pixels, enhanced (spatial filtering and frequency Fourier transform (FFT), manipulated, enlarged, color elimination and isolation, simultaneous comparison

Obtaining Fingerprints o o o Fingers should be clean and dry (alcohol) Individual to right and rear of taker, forearms length from fingerprinting device, ~ 39 inches high Finger should be rolled over ink (thumb toward center, fingers away from center), Tuck other fingers under Ink should cover nail to nail, down to joint Rolled- Individual impression is rolled nail to nail Plain- All fingers at once, then thumb