Forensic Pathology & Autopsy Study Guide

Forensic Pathology & Autopsy Procedure Study Guide

Types of Cases and Causes of Death

  • A body is recovered from the DuPage river.

    • Observation: Bruising around the neck and upper chest region, small cuts and bruises on forearms, little to no water in the lungs.

    • Probable Cause and Manner of Death: Asphyxiation; Manner of Death: Homicide.

  • A man was texting and driving and crashed his car.

    • Result: Spleen burst, leading to death.

    • Probable Cause of Death: Trauma from the accident; Manner of Death: Accidental.

  • A man intentionally takes 6 times his dose of medicine for blood pressure.

    • Result: Death from overdose.

    • Probable Manner of Death: Suicide.

  • A woman was found unconscious in her apartment and transported to the hospital.

    • Outcome: Died with a diagnosed brain aneurysm.

    • Cause of Death: Brain hemorrhage (aneurysm as mechanism); Manner of Death: Natural.

Definitions

  • Autopsy: A detailed and careful medical examination of a person’s body and its organs after death, to help establish the cause of death.

Steps of the Autopsy Process (VIRTUAL AUTOPSY)

  1. External Examination

  2. Internal Examination

  3. Viewing Internal Organs

  4. Removal of Organs

  5. Removal of Brain

  6. Examining the Organs

  7. Returning the Organs

  8. Sewing up the Body

Autopsy Personnel

  • Who performs an autopsy?: Medical Examiner or Forensic Pathologist.

Mortises and Post-Mortem Changes

  • Livor Mortis: The pooling of blood to the lowest parts of the body due to gravity.

    • Begins: 1-2 hours after death.

    • Fixed: 6-8 hours after death.

  • Algor Mortis: The cooling of the body after death.

    • Normal human body temperature: 37 °C.

    • Temperature loss: 0.75 °C/hour for the first 12 hours; 0.4 °C/hour after that until the body reaches room temperature.

  • Rigor Mortis: The stiffness of death.

    • Begins: 1-2 hours after death.

    • Full rigor: 8-12 hours after death.

    • Releases: Due to muscle decomposition, occurring 24-48 hours after death.

Digestive Analysis for Estimating Time of Death

  • Stomach Analysis:

    • Undigested contents: 0-3 hours after last meal.

    • Empty but small intestine full: 4-6 hours after last meal.

  • Small Intestine:

    • Empty with large intestines full: 12 hours after last meal.

  • Large Intestine:

    • Full: 12 hours after last meal.

    • Food found throughout system: 12-30 hours after last meal.

    • Empty (with no food elsewhere): 30+ hours after last meal.

Responsibilities of the Medical Examiner (Forensic Pathologist)

  • At the Crime Scene:

    • Collect the body for examination and autopsy.

  • During the Autopsy:

    • Identify the body.

    • Determine the time of death.

    • Determine the cause and manner of death.

  • In Court:

    • Testify regarding time, cause, and manner of death.

Evidence Collected During Autopsy

  • Aside from organ weights and observations, the following additional evidence is collected:

    • DNA samples

    • Fingerprints

    • Dental impressions

    • X-rays

    • Collection of trace evidence from under the nails.

Autopsy Report Heading Information

  • Information included in the heading of an autopsy report:

    • Case #

    • Medical examiner performing the autopsy

    • Identification of the decedent (name)

    • Location found

    • Time found

    • Position of the body when found.

Estimating Time of Death Through Temperature and Rigor Mortis

  • Scenario Example: Body found in a prone position with certain muscle contractions and discoloration.

    • Rigor indicates death likely occurred 2-8 hours prior.

    • Livor indicates death likely occurred 1-2 hours prior.

    • Conclusion: Likely dead for 2-8 hours.

Temperature Calculations for Time of Death

  1. Calculating Temperature Loss:

    • Example of body temperature loss after 12 hours:

      • Initial body temp (normal): 37^{ ext{o}}C

      • Loss in first 12 hours: 12 imes 0.75^{ ext{o}}C = 9^{ ext{o}}C

      • Remaining: 37^{ ext{o}}C - 9^{ ext{o}}C = 28^{ ext{o}}C

  2. If body found at a certain recorded temperature:

    • E.g., body temp reported as 32.2^{ ext{o}}C:

      • Difference: 37^{ ext{o}}C - 32.2^{ ext{o}}C = 4.8^{ ext{o}}C

      • Equivalent time before death: approx. 6 hours and 24 minutes.

  3. Calculating total temperature lost and time of death:

    • Given a body found at 22.2^{ ext{o}}C:

      • Total temp lost: 37^{ ext{o}}C - 22.2^{ ext{o}}C = 14.8^{ ext{o}}C

      • Temperature loss in first 12 hours: 9^{ ext{o}}C

      • Remaining temp loss: 14.8^{ ext{o}}C - 9^{ ext{o}}C = 5.8^{ ext{o}}C

      • Additional time: 5.8^{ ext{o}}C/0.4^{ ext{o}}C/hr = 14.5 ext{ hours}

    • Total death time from original finding: 12 + 14.5 ext{ hours} = 26.5 ext{ hours}

Super Challenge Example

  • A dead body was found at 10:00 ext{ PM} with a temperature of 20^{ ext{o}}C.

  1. Total temperature lost: 37^{ ext{o}}C - 20^{ ext{o}}C = 17^{ ext{o}}C.

  2. Loss in first 12 hours: 9^{ ext{o}}C.

  3. Remaining temperature lost: 17^{ ext{o}}C - 9^{ ext{o}}C = 8^{ ext{o}}C.

  4. Calculation of time for that loss: 8^{ ext{o}}C/0.4^{ ext{o}}C/hr = 20 ext{ hours}.

  5. Total Time: 12 + 20 ext{ hours} = 32 ext{ hours}.

  6. Calculate probable time of death: 10:00 PM - 32 ext{ hours} = 2:00 PM previous day.