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FORENSIC SCIENCE Johnston High School

FORENSIC SCIENCE Johnston High School

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FORENSIC SCIENCE Johnston High School

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  1. FORENSIC SCIENCEJohnston High School CHAPTER 1: AN INTRODUCTION

  2. Ted Bundy, Serial Killer • Educated individual • Confessed to over 40 murders • All young female • Murdered with blunt instrument/raped • How did he finally get caught? • Forensic ODONTOLOGY!

  3. What is FORENSIC SCIENCE? • Definition: The application of Science to the criminal and civil laws that are enforced by police agencies in a criminal justice system. • Criminal laws – murder, theft, rape, etc. • Civil laws – regulate food quality, environment, pesticides, prescription drugs

  4. History of Forensic Science – Early Developments • Chinese manuscript Yi Yu Ji (Collection of Criminal Cases) • Woman suspected of murdering husband, yet she claims he died in an accidental fire. • How did she get caught? • Limited knowledge of anatomy and physiology delayed development until late 17th/early 18th century

  5. History of Forensics – Initial Advances • Breakthroughs in anatomy and chemistry (late 1700’s) • Carl Wilhelm Scheele and Valentin Ross: found ways to detect poisons (arsenic) in body tissues • Mathieu Orfila – Father of Forensic Toxicology • Tested the effects of poisons on animals

  6. History of Forensics – Later Progress • The Bertillon System • First method of personal/criminal identification • Made by French ethnologist Alphonse Bertillon • Anthropometry • Systematic procedure taking many body measurements • Eventually replaced by fingerprints

  7. Bertillon’s System of Body Measurements

  8. More advancements… • Francis Henry Galton • First to classify fingerprints • First to prove that fingerprints are unique • Hans Gross (1893) • Applied many scientific disciplines and scientific method to the field of criminal investigation • Microscopy, chemistry, zoology, botany, physics, etc.

  9. Who is the best known 19th c. figure? • Sherlock Holmes • Fictional, but many believe creator Sir Arthur Conan Doyle popularized crime detection methods

  10. 20th Century Breakthroughs • Dr. Karl Landsteiner • Discovered that blood can be grouped (A, B, AB, O) • Dr. Leon Lattes (1915) • Simple procedure for determining blood group of dried blood stain • Albert S. Osborn • Developed principles for document examination

  11. Locard’s Principle • Frenchman Edmund Locard • Founder of Institute of Criminalistics at the University of Lyons • Locard’s Prinicple • When two objects come into contact with each other, a cross-transfer of materials occurs. • In other words…EVERY CONTACT LEAVES A TRACE!

  12. More key figures… • Dr. Walter C. McCrone • Expert microscopist • Applied microscopy to annalytical problems in forensics • Calvin Goddard • Used microscopy to study ballistics • Comparing bullets from various guns

  13. CRIME LABS - History • Oldest Forensics Lab = LAPD (1923) • FBI (under J. Edgar Hoover) organized national lab in 1932 – available to all law enforcement agencies across US • Largest forensics lab • Model for state/local labs • Each state has city, county, and state labs • Roughly 350 public crime labs

  14. Growth of Crime Labs • Supreme Court decisions in the 1960’s placed greater emphasis on evidence acceptance/evaluation • Increase in crime rates over last 40 yrs. • More drug-related arrests – chem. analysis • Beginning of DNA profiling • Blood, semen, hair, saliva = possible individualiz.

  15. Major Crime Labs in US • FBI (Dept. of Justice) – Quantico, VA • Drug Enforcement Administration Lab (Dept. of Justice) • Bureau of Alcohol, Tobacco, Firearms, and Explosives (Dept. of Justice) • US Postal Inspection Service

  16. FORENSIC SCIENTIST • Uses REASON to maximize JUSTICE • Applies SCIENCE to LAW • RECOGNIZE • IDENTIFY • EVALUATE • INDIVIDUALIZE physical evidence

  17. FORENSIC SCIENTIST • Independent Finders of FACT • Testify to TRUTH • Use tests that are • RELIABLE • ACCURATE • REPRODUCIBLE • UNBIASED • Evidence cannot be influenced by theories

  18. John F. Kennedy

  19. FORENSIC SCIENTIST • DATA is basis of all conclusions • ACCURATE DATA is derived from careful collection of evidence • POOR EVIDENCE COLLECTION OR HANDLING can result in wrong conclusions • Garbage in – garbage out • DOCUMENTATION IS ESSENTIAL

  20. OJ Simpson

  21. SCIENTIFIC METHOD • What is EVIDENCE vs. COINCIDENCE • Give WEIGHT (ranking) to results • Attach a DEGREE OF CERTAINTY • Break down theories to smallest component and test each • Apply results to theories in order to PROVE or DISPROVE • Components must ADD UP to THEORY

  22. Eyewitness Testimony

  23. What did you notice? At what location was the photograph taken? Glenville Municipal Center How many cars are pictured? 2 What color are the cars? Tan & gray What types of offices are located in the building? Town, police, and court offices How many small trees are in the picture? 2

  24. ORGANIZATION OF A CRIME LABORATORY • Currently – 350 public crime labs operating under federal, state, county and municipal governments • Four major FEDERAL crime laboratories: FBI DEA ATF Postal Service

  25. Laci Peterson, 911, Hurricane Katrina

  26. BASIC SERVICES OF A CRIME LABORATORY • Physical Sciences: Drugs, glass, paint, explosives, soil, fibers, botanic materials, hairs, gunshot residues • Biology: Bloodstains, semen, saliva, DNA • Firearms: Examination of firearms, bullets, cartridge cases, shotgun shells, toolmarks, GSR

  27. BASIC SERVICES OF A CRIME LABORATORY • Document Examination Unit: Questioned documents, inks, papers, forgery, erasures • Photography Unit: Digital Imaging, Infrared, Ultraviolet • Toxicology Unit: Body fluids and organs for drugs and poisons. Intoxilyzer unit • Latent Fingerprint Unit: Processing for fingerprints

  28. BASIC SERVICES OF A CRIME LABORATORY • Evidence Collection Unit - CSI • Polygraph Unit

  29. Other Forensic Science Services • Forensic Pathology • Investigation of sudden, unnatural, unexplained or violent deaths • Autopsy performed to establish the cause of death • 5 categories of death: natural, homicide, suicide, accident, or undetermined • Time of death determined by rigor mortis, livor mortis, and algor mortis

  30. Other Forensic Science Services • Forensic Anthropology • Identification and examination of skeletal remains • Bones can reveal species, sex, approximate age, race and skeletal injury • Facial reconstruction can help identify “John or Jane Doe”

  31. Other Forensic Science Services • Forensic Entomology • Study of insects to estimate the time of death • Insects lay eggs that hatch into larvae • Stages of development tell how long ago the eggs were laid – age of oldest insect on the body dictates minimum post-mortem interval • Temperature and other weather conditions affect the development

  32. Forensic Entomology – Class Project Background • Blowfly (Diptera Calliphora) or Diptera Lucilia • Blowfly egg masses – usually laid in body openings

  33. Entomology – more background • Blowflies detect carcasses within a few hours after death • Come in stages (primary, secondary, tertiary)

  34. Maggots…ewwww • Hairy maggots (Chrysomya) are predacious. • Do not collect with smooth maggots (Calliphora and Lucilia). They will eat the smooth maggots! = poor evidence • With a human cadaver…if you find maggots in places other than body openings = wound

  35. Fly Pupae • Largest larval stage • Forms dark brown casing • Usually left in soil under/around food source • Sometimes wander anywhere from 3m-10m from carcass to avoid competition • PS…collect soil samples too!

  36. Adult Blowfly

  37. Rate of Development depends on… • Temperature • Higher the temp, the faster the insects will develop

  38. Timeline… • Under normal conditions, eggs hatch in 8-12 hours • Maggots take 3-4 days to reach full size • Maggots pupate 1-2 days later • Adults hatch from pupa after 6-8 days • Able to lay eggs 5 days later • So how long has a body been dead if you find adult flies on it? • 13-15 days!

  39. Circle of Life

  40. YOUR ENTOMOLOGY DATA • Date: Monday, Sept. 8th • Time: roughly 1:15pm • Temp: roughly 78-80 degrees F • Flies arrived within minutes!

  41. Another from the 1st day:

  42. Wed, Sept 10 • Time: 11:45am, many flies present • Temp: roughly 70 degrees F • Rained yesterday and

  43. Level 7 Wed. 9/10 • Time: 1:20pm Temp: 70 deg. F, sunny • Observations – large flies, med., white maggots and maggots that JUST hatched, clustered in dark opening, on dried/darker piece

  44. Up close picture

  45. Lev. 6 Thurs. 9/11 • Time: 10:15 am Temp: 62 deg F • Small maggots, numerous, multiple locations on right piece of meat, few flies present

  46. Friday, Sept. 12th • Time: 9:20 am 60 Degrees F • Med – large maggots, dispersed

  47. Sept 12 video by Mike, Lev 7

  48. Monday, Sept 15th (Day 8) • 8:45 am, high humidity, 78 degrees F • 2-3 different species of flies, white unmoving maggots, some moving beneath mud, some small, some medium • Spider present

  49. Mon Sept. 15 Video

  50. Other Forensic Science Services • Forensic Psychiatry • Study of human behavior • Determine if persons are competent to stand trial • Civil: preparing will, settling property • Develop a suspect’s behavioral profile based on previous patterns of other criminals