An autopsy is a specialized examination of a corpse to determine cause and manner of death. There are two types of autopsies - forensic autopsies which are required when criminal activity is suspected or cause of death is unclear, and clinical autopsies which are done to prevent future deaths. Early post-mortem changes like algor mortis, livor mortis and rigor mortis can help estimate time of death. A corpse will decompose in predictable stages over weeks and months, and forensic entomology uses insect evidence to further determine time since death.

1. DRYSDALE CSI
Autopsy.
Ian Anderson
Saint Ignatius College Geelong

2. WHAT IS AN AUTOPSY?

An autopsy (or post-mortem examination) is a
specialized examination of a corpse in order to
determine how and why someone died.
Source: http://www.vifm.org/forensics/medico-legal-death-investigation/a-day-inthe-life-of-a-forensic-pathologist/

3. WHAT IS AN AUTOPSY?

There are two classifications for autopsies:

Forensic autopsy.


Required when:
 Criminal activity is suspected.
 Where the body has not been identified.
 Where the cause of death is not clear.
 Also often required in cases involving accidental death.
Clinical autopsy.

Undertaken in an attempt to prevent future deaths. e.g.
 To investigate a new disease, or
 The effects of a particular treatment.

4. WHAT IS DEATH?

Death is cessation, or end, of life.


How do you determine this?
If you came across someone lying on the ground
and they were cold to the touch and comatose are
they dead?

In the 17th Century anyone in a coma or with a weak
heartbeat were presumed dead and buried.
Many were buried with a bell. Why?
 Saved by the bell!

Source:
http://www.smh.com.au/entertainment/blogs/cinetopia/
top-10-buried-alive-movies-20100929-15x4y.html/

5. THE MANNER OF DEATH.

There are four ways that a person can die:

Natural death.



Accidental death.


When someone deliberately kills themself.
Homicidal death.


Death caused by unplanned events e.g. car accident, falling off
a roof, etc.
Suicidal death.


Interruption and failure of body functions resulting from age or
disease.
The most common manner of death.
The death of one person caused by another person.
Sometimes the coroner will list the manner of death
as ‘unknown’ as a definitive determination of the
manner of death cannot be made.

6. CAUSE AND MECHANISM OF DEATH.

Cause of death.
Describes the event that lead
to a person’s death.
 e.g. stroke, heart attack,
drowning, burning,
strangulation, etc.


Mechanism of death.

Describes the specific change
in the body that brought about
the cessation of life.

e.g. loss of blood, cardiac arrest,
cessation of brain function, etc.
Source:
http://www.news24.com/SouthAfrica/News/Richard
s-Bay-man-missing-feared-drowned-20121120

7. TIME OF DEATH.

Estimation of the time of death can be important
in cases of suspicious death.


e.g. a suspect may be proven innocent because they
were not in the same place as the victim at the time
of death, or a suspect may remain a person of interest
because they were in the same area as the victim at
the time of death.
Early post-mortem changes can be used to
determine the time that has elapsed since death
occurred (called post-mortem interval).

This because the body changes and eventually
decomposes in predictable ways after death.

8. TIME OF DEATH.

Early post-mortem changes.

Algor mortis (changes in body temperature).


The most accurate measure available for estimating the time of
death (particularly in the first 18 hours post-mortem)
When alive our body temperature is ~37°C. After death the
body cools (or heats) at a predictable rate until it reaches the
surrounding environmental temperature.
 Approximately one hour after death the body cools at a rate
of 0.78°C per hour. After 12 hours the body loses about
0.39°C per hour until it reaches the same temperature as its
surroundings.
 Other factors (e.g. size of the victim, what they are wearing,
atmospheric conditions, etc.) may alter the cooling rate.
 Changes in decomposition after approximately 42 hours
post-mortem will result in the core body temperature rising
slightly.

9. TIME OF DEATH.

Early post-mortem changes.

Livor mortis (Hypostasis).
Post-mortem, blood settles in the lower blood vessels of the
body due to gravity, resulting in discolouration of tissues
(lividity).
 The extent of livor mortis in various tissues can help to
determine the post-mortem interval, the position of the
body at death and whether it has been moved.
 Develops shortly after death; becomes apparent within 2
hours; is fully developed after 3-4 hours; and usually
lasts until decomposition.
 A less reliable indicator of time of death than rigor mortis.

Source: Bertino & Bertino, 2012

10. TIME OF DEATH.

Early post-mortem changes.

Rigor mortis (Hypostasis).
The stiffening of the body that occurs in the early stages
after death.
 Immediately after death the body is flaccid, however
within two hours the stiffness starts in the head and
gradually works its way down to the legs. The stiffness
gradually disappears after 36 hours.
 Occurs because the skeletal
muscles temporarily contract
and cannot relax.
 Not as accurate as measuring
core body temperature, but
more accurate than using
livor mortis.

Source: http://forensics4fiction.com/2011/08/19/estimating-thetime-of-death-rigor-mortis-2/

11. TIME OF DEATH.

Early post-mortem changes.

Stomach & intestinal contents.


The amount of food found in the stomach and/or in the
intestines can be used to determine time of death.
 If undigested food found in the stomach, then death
occurred 0-2 hours after the last meal.
 If the stomach is empty, but food is found in the small
intestine, then death occurred 4-6 hours after a meal.
 If the small intestine is empty, but wastes are found in
the large intestine, then death probably occurred 12 or
more hours after a meal.
Changes to the eye.

Following death the surface of the eye dries out and a thin
film forms 2-3 hour later if eyes were open, and within 24
hours if the eyes were closed at death.

12. TIME OF DEATH.

Insect evidence.

Insects can provide detailed evidence about the time
of death due to the sequential colonisation of dead
bodies by insects.
Source: http://www.forensictopics.com/forensic_entomology
We will look at forensic entomology in detail later.

13. STAGES OF DECOMPOSITION.

A corpse will decompose in a predictable way
over time.

Within 2 days.
Green & purplish staining occurs from blood decomposition.
 The skin takes on a marbled appearance.
 The face becomes discoloured.

Source:
http://en.wikipedia.org/wiki/Forensic_entomological_decomposition

14. STAGES OF DECOMPOSITION.

A corpse will decompose in a predictable way
over time.

After 4 days.
The skin blisters.
 The abdomen swells due to the CO2 released by bacteria
living in the intestines.

Source:
http://en.wikipedia.org/wiki/Forensic_entomological_decomposition

15. STAGES OF DECOMPOSITION.

A corpse will decompose in a predictable way
over time.

Between 6-10 days.
The corpse bloats with CO2 as bacteria continues to feed on
tissues. Fluids leak from the body cavities as cell
membranes rupture.
 Eyeballs and other tissue
liquefy.
 The skin sloughs off.


Between 20-30 days.
The gas causes the
abdominal cavities & chest
to burst and collapse.
 Tissues continue to liquefy
and gradually dissolve.

Source:
http://en.wikipedia.org/wiki/Forensic_entomological_decomposition

16. STAGES OF DECOMPOSITION.

A corpse will decompose in a predictable way
over time.

After 30 days.
The corpse begins to dry out.
 When most of the flesh is gone, further decay is very slow
from lack of moisture.

Source:
http://en.wikipedia.org/wiki/Forensic_entomological_decomposition

17. A DAY IN THE LIFE OF A FORENSIC PATHOLOGIST.
Source: http://www.vifm.org/forensics/medico-legal-death-investigation/a-day-inthe-life-of-a-forensic-pathologist/

18. http://sick9CSI.wikispaces.com/