Transcript The Forensic Autopsy

The Forensic Autopsy
What is an Autopsy?
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“See for yourself”
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A post mortem
examination
preformed to
determine the cause
of death.
Why is a Forensic Autopsy
preformed?
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Cause of death
deemed suspicious,
or involves criminal
action.
Experts Who Perform Forensic
Autopsies
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Forensic Pathologist, aka a Medical Examiner
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4 years Undergrad
4 years Medical School
4 years Pathology “Residency”
Forensic Pathologist
a sub-specialty of pathology that focuses on determining the cause of death by examining a
corpse.
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Autopsy - a postmortem examination to discover the
cause of death or the extent of disease.
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Autopsy's are normally are called upon when the
death is:
 Sudden
 Violent
 Unexplained
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Investigators will look into
 Manner
 Mechanism
 Cause
 Time
Manner of Death
In a forensic autopsy,
a medical examiner or
coroner declares the death
to be:
 Natural
 Accident
 Homicide
 Suicide
or
 Unknown
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Natural Death
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Caused by a known disease: cancer, heart
disease, stroke, genetic disorders, etc.
Often just simply “old age”
Accidental Death
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Caused by mistake or freak occurrence.
Death not planned, but can be explained
by circumstances.
Homicidal Death
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Killing another person.
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Close to you?
 Infanticide, Fratricide, Sororicide, Parricide, Patricide,
Matricide, Mariticide, Uxoricide
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Lots of people…
 Genocide – Killing a national, ethnic, racial or
religious group
Homicide is the most investigated death, therefore the
most autopsied.
Suicidal Death
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Killing of self.
Often the easiest to identify wrt cause.
Can be elaborated further in the report…
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Toxic, firearm, blunt force trauma,
asphyxiation, etc.
Unknown Death
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Deaths in absentia
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At sea
Badly decayed bodies
Mechanism of Death
The physiological dysfunction that results in the
death.
Example: death due to the gunshot wound, the
mechanism is exsanguination (extreme blood loss).
Cause of Death
The disease or injury that produces the
physiological disruption inside the body resulting in
death.
Example: a gunshot wound to the chest.
Protocol for Performing
A Forensic Autopsy?
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Corpse brought to M.E.
In a new body bag/clean sheets
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Avoids cross-transfer of evidence
Placed on dissection table
Physical Examination
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2 Parts:
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External
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Physical outer layer – for injuries / cause of death
Internal
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Internal organs & tissue - evidence of disease,
trauma, toxic substances, organ failure
External Examination
Steps:
1. Photographed
2. Samples taken: hair, nails
3. Undressed, examined for wounds
-- Lacerations, abrasions, bruises
4.
Measured, weighed, cleaned
Internal Examination
Steps of an internal examination.
1. Incisions
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“Y”… Behind each ear, down the neck, meet
mid-sternum, continue to the groin.
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For suspected strangulation – 50% no ext. signs
Show fractured HYOID bone
“T” … From each shoulder, meet top of
sternum, continue to the groin.
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Better looking finished product
Hyoid
Internal Examination (cont’d)
2.
Cuts
Chest cavity cut open w/shears or saw.
3.
Removal
1.
2.
4.
Letulle’s “En Masse” method – All organs at once
Ghon’s “En Bloc” method – Organs removed in
sections
Organs weighed, examined
Internal Examination (cont’d)
5.
Brain examination
1.
2.
3.
4.
Incision: from a point behind one ear, over
top of head, to point behind the opposite ear.
Scalp pulled away from the skull, forward and
back. Front flap over the face, rear flap over
the neck.
Skull cut with electric saw…creates a “bowl”
Brain cut from spinal cord, lifted out of the
skull for further examination.
Internal Examination (cont’d)
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In addition…Major Systems looked at
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Cardio-Vascular (Heart & Lungs)
Central Nervous System (CNS)
Vitreous Humor
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Not much?
= Dead longer…
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More Potassium?
= Dead longer…
Broken blood vessels?
= likely strangulation
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http://forensics.rice.edu/
Livor Mortis
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Meaning…Dis- ‘Color of Death’.
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Coloration of the skin.
Death = the heart stops = blood stops cycling.
 Red blood cells, plasma gather on the bottom part
of the body, closest to the floor.
 A line forms after 8 hours if the body hasn’t been
moved. If moved, a new line forms.
 The thicker the line, the longer the body held that
position.
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3. Livor mortis
Algor Mortis
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Defined as ‘Coolness of Death’.
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Temperature of body.
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In a controlled environment, stating at 98.6 degrees, the
body will drop one degree per hour.
This happens because at death, the respiratory system stops
working, the body stops functioning, it is no longer moving.
When taking the temperature of a corpse, you can’t take it in
the mouth because the muscles will be relaxed and the
tongue wont stay on top of the thermometer.
Thinner people cool faster then fat people.
Rigor Mortis
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Defined as ‘Stiffness of Death’.
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Flexibility of the body.
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Shows up 2 hours after death
Peaks 12 hours after death.
Takes 12-24 hours for entire rigor mortis effect to take place.
At approximately 20 hours after death, the body is at its
stiffest.
The eyelids are affected first, the the jaw, face, trunk, arms,
legs.
Ends after 24-36 hours.
Factors affecting Rigor mortis ?
1.Ambient temperature,
• Cooler the body the slower the onset of
rigor
2.Person’s weight
• Fat stores more oxygen and slow rigor
3. Type of clothing
• Helps keep the body warm
Pallor Mortis
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Defined as ‘Paleness of Death’.
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Tone of the body.
Happens 15-20 minutes after death.
 Happens due to lack of capillary circulation in the
body.
 Can not be used to determine time of death except
if body is found still with color.
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Estimating Time of Death
1. Algor mortis: reduction in body temperature following
2.
3.
4.
5.
6.
7.
8.
9.
death
Rigor mortis: stiffening of the body after death
Livor mortis: (Lividity) : settling of the blood in the
lower portion
Potassium levels in vitreous humor + Clouding of the
cornea
Digestive Contents
Evidence of Decompositional Process
Presence/absence of purge fluids
Drying of the tissue
Insect Larval Instars
Digestive Contents
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Stomach empties contents after 4-6 hrs
Small intestine empties after 24 hrs
Colon empties 24-48 hrs
Stages of Decomposition
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2 days
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Cells autolysis
Greenish purple staining occurs, blood decomposing
Skin takes on Marbled Appearance
4 days
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Skin blisters
Abdomen swells with carbon dioxide
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Due to bacteria in intestines
6-10 days
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Corpse bloats with CO2
Corpse eventually bursts
Fluid begins leaking from openings as cell
membranes rupture
Eyeballs liquefy
Skin sloughs off
Forensic entomology
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Entomology is study of insects
Complete Metamorphosis
72 hrs
50 hrs
23 hrs
35 hrs
130 hrs
143 hrs
Blowflies are usually the 1st
invader
Can lay eggs within 20
minutes of death
Beetle larvae
Ta Da!
The End