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INVESTIGATIONS

INVESTIGATIONS

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INVESTIGATIONS

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  1. INVESTIGATIONS SCIENCE OR ART?

  2. 3.5 THINGS SOLVE CASES THEY ARE?

  3. WITNESS • PHYSICAL EVIDENCE • CONFESSIONS

  4. .5 • INFORMANTS • CANNOT BE USED TO PROVE • NOT USUALLY USED IN COURT

  5. SUCCESS OR FAILURE OF CASE • People commit crimes • “THINGS” become physical • evidence • What is PHYSICAL EVIDENCE

  6. PHYSICAL EVIDENCE---any object that can establish that a crime has been committed or can provide a link between a crime and its victim or between a crime and its perpetrator

  7. CAN BE MEASURED

  8. TYPES OF PHYSICAL EVIDENCE • Blood, semen, saliva • Documents • Drugs • Explosives • Fibers • Fingerprints

  9. Firearms, and ammunition • Glass • Hair • Impressions • Paint • Soil and minerals • Tool marks

  10. WHOSE ARE THOSE ANYWAYS?? • Individual characteristics---Properties of evidence that can be attributed to a common source with an extremely high degree of certainty.

  11. HISTORY OF IT ALL • Sir Arthur Conan Doyle • A Study In Scarlet • 1887

  12. MID 1800’s • NYPD set up a Rogue’s Gallery-1857 • Photographs of known offenders • Arranged by criminal specialty and height • Offenders grimaced, puffed their cheeks to change their appearance

  13. Rogue is slang for thieves, a wandering beggar, someone who wanders away • By 1858 had over 700 photographs

  14. 1884 Chicago established the first municipal Criminal Identification Bureau • 1865 U.S. Secret Service was created by Congress to combat counterfeiting • Began guarding the president in 1903 after President McKinley was assassinated • 1905 CA Bureau of Criminal Identification

  15. First State Police Force in Pennsylvania • Prohibition in 1920, Bureau of Internal Revenue was responsible for enforcement • Lodged in the Dept of the Treasury, they were referred to as “T-men” • 1908 the beginnings of the FBI • 1932 FBI established a crime lab

  16. 1967 National Crime Information Center (NCIC) established by the FBI • Wanted persons • Stolen property • Guns • Vehicles • License plates • Cannot do credit cards

  17. “PACKING THE RECORD” • Get as much information as possible

  18. NCIC INFORMATION CLEARING HOUSE • COMPUTERIZED NETWORK LINKED TO PDs TO PROVIDE INFORMATION ON • STOLEN VEHICLES • WANTED PERSONS • STOLEN GUNS • OTHER CRIME RELATED INFO

  19. Oldest Forensic Lab • LAPD---1932 • Created by August Vollmer • Chief from Berkeley

  20. LOCARDS EXCHANGE PRINCIPLE • Edmond Locard (1877-1966) • The exchange of materials between two objects that occurs whenever two objects come into contact with one another

  21. TRACE EVIDENCE • PHYSICAL EVIDENCE THAT RESULTS FROM THE TRANSFER OF SMALL QUANTITIES OF MATERIAL

  22. IDENTIFICATION • THREE MAJOR SCIENTIFIC SYSTEMS FOR PERSONAL IDENTIFICATION • DEOXYRIBONUCLEIC ACID (DNA) TYPING • ANTHROPOMETRY • DACTYLOGRAPHY

  23. ANTHROPOMETRY • A system of identification of individual by measurement of parts of the body

  24. ANTHROPOMETRY • Developed by Alphonse Bertillon (1853-1914) • Father of criminal identification • Bertillon system • Every human being differs from every other one in the exact measurements of their body and that the sum of these measurements yields a characteristic formula for each individual

  25. Eleven physical measurements • 1883 implemented on an experimental basis • Combines full fact with profile pictures • Ancestor of the “mug shot”

  26. DACTYLOGRAPHY • Dates back to the First Century Romans • Three categories of latent fingerprints • Plastic prints—fingers touch against a surface such as newly painted surface, adhesive on envelopes and stamps, explosives, thick layer of dust, putty and adhesive tape

  27. LATENT • LATIN WORD FOR • HIDDEN

  28. Unique and Permanent • They develop at 12 weeks development • Stresses in the uterus causes friction ridges to develop • Identical twins have same DNA but different fingerprints---but may have same pattern types

  29. FRICTION RIDGES • TINY RIDGES IN THE SKIN OF A FINGERPRINT ARE KNOWS AS; • FRICTION RIDGES

  30. LOOPS

  31. WHORLS

  32. ARCHES

  33. WHAT TO LOOK FOR • LOOPS 60-65% OF POPULATION • WHORLS 30-35% • ARCHS About 5%

  34. Contaminated/visible prints—fingers that have been contaminated with a matter touch a clean surface • Latent/invisible prints—typically invisible to the unassisted eye. Created when the friction ridges deposit oils and body perspiration on a surface

  35. PRINTS ARE MADE OF: • Natural source—Sweat (98% water and 2% oils) Salts and amino acids and vitamins cause the fingerprint to show when sprayed with a chemical • Environmental source—grease, dirt, pollen, etc.

  36. DEVELOPING LATENT PRINTS • Traditional powders • Fluorescent powders • Chemicals • Cyanoacrylate—Superglue fuming • Ninhydrin • Iodine

  37. CHANGE THEM???? • Impossible to obliterate all the ridge characteristics and scars just help to provide new characteristics for identification

  38. LIVE SCAN FOR FINGERPRINTING • OPTICAL SCANNER

  39. IAFIS FBI 1999 • INTEGRATED AUTOMATED FINGERPRINT IDENTIFICATION SYSTEM

  40. BRAIN FINGERPRINTING

  41. OTHER TYPES OF IDENTIFICATION • DENTAL EVIDENCE & BITEMARKS • 1775 Paul Revere—was a dentist • John Wilkes Booth • mid 1960’s Armed Forces • Used mainly for id of bodies • 1970’s used for id of suspects

  42. HAIR • Area of the body and race • Manner removed • Shampoo residues • Bleached or dyed • Contaminants in the hair—blood, soil semen • If hair has been subject to trauma • Id of drugs ingested

  43. BLOOD • Approx 10 pints of blood • Most common form of evidence • Human blood? • If recovered in liquid state can tell • Venous • Fetal • menstrual

  44. HUMAN EXCRETIONS AND SECRETIONS • Saliva, urine, semen, perspiration, vaginal secretions, feces and vomitus • LIPSTICK AND SECRETIONS • Everyone has unique lip prints that do not change with age • FIREARMS

  45. TOOL MARKS • DOCUMENTS • HANDWRITING AND HANDPRINTING • COMPUTERS

  46. MOLECULAR STUCTURE DNA • DEOXYRIBONUCLEIC ACID • Organic substance found primarily in the chromosomes within the nuclei of cells. These molecules carry the body’s genetic information and establish each person as separate and distinct • DNA is three foot long chemical that is tightly wound inside the 46 chromosomes in each cell of the body

  47. HISTORY OF DNA • FBI first public sector crime laboratory to accept cases for DNA • December 15, 1988 • Minnesota testing is done at the Bureau of Criminal Apprehension (BCA) • Testing can take from 2 weeks to 2 months

  48. CODIS 1998 • COMBINED DNA INFORMATION SYSTEM • COMPARE AND • EXCHANGE DNA PROFILES