1. Notes: Death and Autopsy

2. Notes: Manner of Death Natural Accidental Suicidal Homicidal
Undetermined

3. Cause and Mechanism Cause: the reason someone dies
Disease
Physical Injury
Stroke
Heart Attack
Proximate Cause: underlying cause of death, as opposed to final cause.
Ex: Smoking is the proximate cause that leads to lung cancer.

4. Cause and Mechanism
Mechanism of death: specific change in the body that brought about the cessation of life.
Ex: Cause – Gunshot / Mechanism – Blood Loss

5. Questionable Traumatic Deaths
When there is a questionable traumatic death, a pathologist to perform an autopsy
Traumatic deaths are classified into four categories:
1. Mechanical: strangulation, sharp and blunt force traumas, gunshots
2. Thermal: exposure to extreme heat or cold
3. Chemical: death resulting from the use of drugs and poisons (both legal and illegal)
4. Electrical: caused by an electrical charge that is passed through the body
Can cause ventricular fibrillation (heart attack)

6. What is Forensic Pathology?
Pathology: the study of disease
Forensic Pathology: uses a thorough knowledge of the human body to uncover facts about a crime.

7. Who is the Forensic Pathologist? (Don’t need to write….)
Education
4- year college degree
4 years of medical school
Residency program for an additional 3-5 years
Training in the subspecialty of forensics at a fellowship training program for 1-2 years.
Salary
$60,000-$200,000

8. When do Pathologists Become Involved? (Don’t need to write…)
When a sudden, suspicious, or accidental death occurs
Uses medical knowledge to determine when, how, and why the victim died
Also identifies unknown victims
Must be willing to testify in court

9. 5 Critical Questions Who is the deceased? What is the cause of death?
Factor the directly caused the victims death – bullet, poison..
What is the mechanism of death?
Change in the body that took place as a result of the cause of death – fatal loss of blood, heart failure
What is the manner of death?
Accidental, suicide, homicide, natural or undeterminded
When did they die?

10. Examining the Body
The ME chooses from three types of autopsies: external, partial, and internal
External
Examine just the outside of the body when the cause and manner of death are clear
Scars, preexisting and postmortem injuries, trauma, trace evidence, and any postmortem changes in the appearance of the body

11. Examining the Body Partial Internal
Cause and manner of death are not obvious, so you must complete an external exam followed by a detailed exam of one part of the body
Look closely at the brain, chest area for heart disease, abdominal cavity for irregularities
Internal
Investigation of all the organs, tissues, and fluids of the body

12. The Postmortem Interval
Postmortem Interval: length of time a person has been deceased
Most accurately done if body has been found within the first 24 hours of death
Determined using algor, rigor, and/or livor mortis

13. Time of Death Livor Mortis “Death color”
Purplish color is visible on parts of the skin wherever the blood pools.
Known as lividity.
Can determine time of death, the position of the body during the first eight hours after death, and if the body has been moved.
Begins 2 hours after death and becomes permanent after 8 hours.

14. Time of Death Rigor Mortis
“Death Stiffness”
Starts within 2 hours after death and remains 48 hours after death
Without oxygen, calcium accumulates in the muscles.
Calcium is used by the body to signal muscle contraction, this accumulation signals the muscles to contract.
The muscles become stiff.
Rigor mortis starts in the head and works its way down to the legs.

15. Time of Death Rigor Mortis
2 -6 hours postmortem (after death), rigor begins in the head
12 hours postmortem, rigor is complete and throughout the entire body
hours postmortem, the muscle fibers begin to dissolve, and softening begins (rigor mortis starts to end).
hours postmortem, rigor ends and is relaxed throughout the entire body.

16. Time of Death Factors that Affect Rigor Mortis Ambient temperature
(cold = slow rigor)
The weight of the body
(obesity = slow rigor)
The body’s clothing or lack of it
Any illness the person had at the time of death
The level of physical activity at the time of death
Sun exposure

17. Time of Death: Algor Mortis
In death a body no longer generates warmth and begins to cool down.
To find the standard temperature of a corpse, a thermometer is inserted into the liver.
Body heat is lost at about 1 to 1.5 degrees an hour.
Time of death determined by temperature calculations is expressed as a range of time.

18. Time of Death Algor Mortis First 12 hours after death:
Body cools 0.78 °C (1.4 °F) per hour
After 12 hours after death:
Body cools 0.39 °C (0.7 °F) per hour
Example
What is the temperature loss for someone who has been dead for 12 hours?
0.78 ° C x 12 hours = 9.36 ° C

19. Time of Death Stomach Contents
4-6 hours for stomach to empty contents into small intestine
Another 12 hours for the food to leave the small intestine for the large intestine
24 hours for the food to leave the large intestine

20. Time of Death – Stages of Death
Initial Decay
Putrefaction
Black Putrefaction
Butyric Fermentation
Dry Decay

21. The Body Farm (Don’t need to write…)
Research facility at the University of Tennessee
Studies decomposition in various setting for law enforcement
Western Carolina University now has a body farm

22. Decomposition Stage-1 Initial Decay 0-3 days
Marbling appears on skin
Bacteria in intestine begin to digest body
Bodies own enzymes start to digest tissues

23. Decomposition Stage 2 – Putrefaction 4-10 days
Odor of decaying flesh is present
Body swells dues to gases produced by fermenting bacteria
Fluids leak from body openings as cell membranes rupture
Eyeballs and other tissue liquefy

24. Decomposition Stage 3 – Black Putrefaction 10 –20 days
Very strong odor
Bloated body has collapsed
Exposed tissues are black in color
Fluids drain from body
Skin sloughs off

25. Decomposition Stage 4 – Butyric Fermentation 20-50 days
Most of the flesh is gone
Body dries out
Ground around the body becomes moldy

26. Decomposition Stage 5- Dry Decay 50-365 days
Body is dry
Eventually only the bones will remain

27. Forensic Entomology
Using the life cycle of insects to determine time of death

28. Time of Death: Insects
Blowfly eggs can be found in the moist, warm areas of a corpse within 8 hours after death.
They will have progressed to the 1st of their 3 larva stages (illustration of one shown above) within 20 hours.
By the 4th or 5th day they will have progressed to the 3rd of their 3 larva stages.

29. Time of Death: Insects
By the 8th or 12th day the larvae will migrate away from the corpse to a dry place.
Becoming pupa and immobile within days, they will change from white to dark brown.
By the 21st-24th day the pupa cases will split open and adult blowflies (illustration of one shown above) will emerge.

30. Time of Death: Insects
Because scientists know how long it takes for the various stages of development at given temperatures, forensics entomologists can determine when the insects arrived.
Because life cycles are affected by fluctuations in the daily environmental conditions, insect evidence cannot provide an exact time of death.
Insect evidence, nonetheless, can yield a close estimate.