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Chapter 13 - Process of Death


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Chapter 13 - Process of Death

  1. 1. The Process of death Chapter 13 Forensic Science Mrs. Morgan
  2. 2. Confirming Death• Although it may be obvious, any death must be confirmed by a trained professional – usually a doctor, coroner or medical examiner• Must meet the criteria of death – then pronounced dead• Body can then be moved, handled and processed if necessary
  3. 3. At the crime scene• A dead body found at a crime scene is handled and processed by the medical examiner’s office• Officers and CSIs cannot touch or move the body until the ME has given permission to do so• Any evidence on a body is collected by the ME staff and turned over to the crime lab
  4. 4. Time of Death Algor Mortis: Body cooling rate• The body slowly cools once the heart stops beating• Measuring body temperature can approximate the time of death• Use liver temperature• Can be influenced by the environment or internal conditions
  5. 5. Click to Time of Death edit Master title style• Calculating time of death – Glaister EquationHours since death = 98.4°F – internal body temperature 1.5• Used as a starting point to determine time of death – ultimately use other factors to corroborate a more accurate time
  6. 6. Changes to the body Livor Mortis: skin discoloration caused by the pooling of blood• When heart stops beating, blood pools and coagulates in lower portions of the body due to gravity – creates red/purple blotches• Can show the position of body after death• May indicate if the body has been moved or repositioned
  7. 7. Post-Mortem Lividity•Starts 30 min – 3 hours after death•Maximum lividity 6 – 12 hours after death Parts of body touching the ground/surface show no lividity due to compressed capillaries
  8. 8. More changes Rigor Mortis: rigidity of skeletal musclesIn humans:•starts after about 3 hours•reaches maximum stiffness after 12 hours•gradually dissipates until approximately 72 hoursafter death. I don’t know – I googled “rigor mortis” and this was one of the top hits…
  9. 9. Overall timetime death Overall of of death• Pathologists will use multiple factors to calculate TOD• Always a small margin of error Temperature of Stiffness of body Time since death body Warm Not stiff Not dead more than 3 hours Warm Stiff Dead between 3 and 8 hours Cold Stiff Dead between 8 and 36 hours Cold Not stiff Dead for more than 36 hours
  10. 10. Stages of DecompositionInitial or fresh decay(autolysis): The cadaver appearsfresh but is decomposing internallydue to the activities of bacteriapresent before death (0-4 days).Putrefaction or bloating: Thecadaver is swollen by gas producedinternally, accompanied by theodor of decaying flesh (4–10 days).
  11. 11. Stages of DecompositionBlack putrefaction: Flesh ofcreamy consistency, with exposedbody parts black. Body collapses asgases escape. Fluids drain. Odor ofdecay very strong (10–20 days).Butyric fermentation: Cadaverdrying out. Some flesh remains atfirst; cheesy odor from butyric acid(20–50 days).
  12. 12. Stages of DecompositionDry decay (diagenesis):Cadaver almost dry; slow rate ofdecay. May mummify (50–365days). All of the changes that accompany decomposition are subject to variation based on individual characteristics and the environment
  13. 13. The autopsy• Performed to determine cause and manner of death, discover the extent of disease or for teaching purposes• Forensic autopsies have legal implications• Performed by a pathologist – specially trained MD
  14. 14. Who & why• ME can order an autopsy• If not – need permission from next of kin• Autopsied people include – Suspicious deaths – Not under the care of a doctor – Died during an operation• Family can limit scope or request specific procedures be followed
  15. 15. The toolsStryker saw – used to cut through the skull to remove the brainStandard tools used in an autopsy
  16. 16. Autopsies – the outside• Starts with thorough external exam – Physical attributes – Scars and/or tattoos – Evidence of wounds/bruises – All findings diagramed and recorded in detail
  17. 17. Autopsies – the inside• Body is open with a Y-incision to expose the thoracic and abdominal cavities – Shoulders to pubic bone• Ribs are cut to expose the heart and lungs• Organs are removed, weighed and examined
  18. 18. Finishing upTissue and fluid samples aretaken, analyzed and stored Organs returned to proper place in cavities and incisions are sewn up