Forensics MIdterm part 3

  1. Bertillion system
    first system used to identify criminals
  2. Alphonse Bertillion Anthropometry
    physical measurements to identify individuals and who made this up
  3. portrait parle'
    photographs and body measurements
  4. william hershel
    required natives to sign contracts with an imprint of their hand, began lifelong study
  5. henry foulds
    in scotland used fingerprints in a criminal setting freeing a suspect
  6. francis galton
    publishes the book fingerprints and group patterns into loops, whorl, demenstrates no two prints are identical
  7. A fingerprint is an individual characteristic, no two fingers have yet to been found to possess identical ridge characteristics
    1st fundemental principle of fingerprints
  8. level 1: flow of ridges, pattern type
    level 2: minutiae (points)
    level 3 shape/ structual of ridge units pores
    indiviuality is determined by ( finger prints and levels)
  9. Analysis (level 1,2,3)
    Verification ( by someone else)
    ACE-V methodology
  10. ACE-V methodolgy
    assures validity and reliability
  11. a fingerprint remains unchanged during an idividuals lifetime
    2nd fundemental principle of fingerprints
  12. fingerprints have general ridge patterns that permit them to be systamatically classified
    3rd fundemental principle of fingerprints
  13. plastic prints
    created when fingers touch material such as wet paint, oil films, putty, tape, dust
  14. Visible prints (patent prints)
    created when fingers contaminated with foreign matter such as soot, blood, and ink touch a surface
  15. invisible (latent)
    created when fingers with small amount of body oil and perspiration touch a surface
  16. surface smooth or textured
    nature if material
    how the object was handed
    amount of concentration ( too much vs. too little)
    suspect wearing gloves
    environment conditions
    Quality of print or failure to find prints at scene affected by
  17. powders
    iodine fuming
    physical developer
    super glue fuming
    methods of detecting
  18. powder
    • goal is to provide contrast between the pront and the surface
    • Black, white, magnetic silver, red, duel-contrast, floresent

    apply small amount of .... to brush and then dust areas very smooth light strokes
  19. chemicals
    amido black-... used with bloody prints reacts with proteins turns print blue black
  20. Leuco Crystal violet (LCV)
    used with bloody prints, reacts with hemoglobin turns print to purple/violent color
  21. Ninhydrine
    reacts to amino acids and is used with paper and cardboard turns prints purple blue heat applied to hasten
  22. Small Particle reagent (SPR)
    adheres to the lipids and used to surfaces that are wet
  23. physical developer
    silver nitrate based liquid with porous surface
  24. superglue fuming
    • Cyanoacrylate nonporous surfaces such as metal tape, leather. heating of this in a chamber interacts with fingerprints
    • prints are then enhanced in a chamber interacts with fingerprints then enhanced with powder or dye stains protect print and does not affect DNA (after)
    • can do it on as small as a knife or as big as a car
  25. Laser and Alternative light sourse (ALS)
    • prints (perspiration) with fluroses or glow and can be viewed with googles/filters
    • photographs or enhanced with flourscent powders/dyes
  26. 1. close-up photographs
    2. collect them
    3. tape life
    4. gelatin lifters
    5. casting material:accurtans microsil
    How to collect of latent lifts
  27. Hair
    cannot individualize a any single head or body through morphology or structural characteristics
  28. 1. anagen phase
    2. catagen phase
    3. telogen phase
    3 stages of hair
  29. anagen phase
    • initial growth up to 6 years
    • follicular tag: piece of tissue surrounding the shaft that contains the richest sourse if DNA
  30. catagen phase
    a transition stage between the anagen and telogen phases of hair growth
  31. telogen phase
    the final growth phase in which hair naturally falls out of the skin
  32. follicular tag
    a translucent of tissue surrounding the hair's shaft near the rot that contains the richest source of DNA associated with hair
  33. human vs. animal
    species of animal
    comparing questioned hair to standard
    look @ color, length, diameter, presence of medulla distribution shape color intensity dyed/bleach
    estimate of time sence dying or bleaching can look at hair for drug use.
    Hair identification and comparison
  34. yes (pubic , beard , head)
    Can we tell which body area hair comes from
  35. yes with caution
    can we tell what race the hair came from
  36. age no expect infants
    sex no styles preclude sex
    Can we tell age and sex with hair
  37. yes
    can we tell if hair is forcably removed
  38. nuclear DNA
    • with root or follicular tag can individualize hair
    • higher success during ANAGen phase
  39. mitochondral DNA
    • cellular material outside of nucleus
    • maternally inherited
    • 2 cm needed for best results
    • cant individualize
    • diversity within human population permits exclusion
  40. presumptive
    microscopic hair is .......
  41. need adequate number of standard/reference sample victim, suspect, other with access usually head or pubic hairs
    need 50 from all areas of scalp 24 pubic hairs pulled or cut at skin line
    sexual assult kits :combing of public hairs
    collection of hair (general)
  42. tape lifts
    tweezers with bindle
    collect item
    collection of hair (at crime scene)
  43. Fibers
    • mass production has limited the value of ....evidence
    • rarely provide individualization
  44. torn edges (break match) fitted together can produce individualization
    microscopic comparison of color and diameter
    look at length straiations, pitting on surface, cross-sectional shape dyes chemical comparison use visible light
    significance of fiber evidence depends on location number and nature of fibers
    identification and comparison of fibers
  45. tape lifts
    collect item and package seperately
    tweezers and bindle
    standards/reference samples
    alternate light sourse (aLS)]
    collection of fibers
  46. microscope serectmicrope
    examine color surface texture color layer structure layer structure very important
    number and sequence
    break match can provide individuality
    chemical analysis
    gas chromatograph
    paint identification and comparison
  47. tweezers in bindle (tape life)
    scraped off with new razor blade (all layers)
    collect item
    carefully package clothing
    standard/reference sample
    undamaged area of car close to transfer
    done to bare metal
    1/4 inch square
    collection of paint
  48. break match can provide individualization
    general chemical composition is to uniform
    look at density and refraction (class characteristics)
    eliminate people
    GLass identification and comparison
  49. radial fracture
    a crack in a glass that extends outward like a spoke of a wheel from the point at which the glass was struck
  50. concentric fracture
    a crack in a glass that forms a rough circle around the point of impact
  51. stress marks
    shaped like arches and are perpendicular to one surface and curved parallel to the other
  52. opposite
    edge of radital crack-perpendicular end is always .........the side of the force
  53. faces
    edge of concentric crack perpendicular and always.... the surface where the force originated
  54. Radical cracks form a Right angle on the Reverse side of the force
    3 R
  55. need standard/reference samples
    collect from remaining glass in window or door
    close to point of breakage
    1 square inch
    package in solid container
    wrap clothing/shoes (burglary)
    for direction of impact need to mark "inside: and outside
    Glass collection
  56. cold filament (cold shock)
    will break during contact
  57. Hot filament (hot shock)
    will stretch and deform
  58. soil
    • any disintegrated surface material natural or artifical that lies near the earths surface
    • rocks, minerals, vegatation, asphalt, brick, fragments cinders
Card Set
Forensics MIdterm part 3
CH 7,12,13,8