Death

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Death

• Meaning, manner, mechanism, cause and time

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Death

1. Meaning
2. Manner
3. Mechanism
4. Cause
5. Time

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How do we define Death?

• Is a person with a heartbeat alive even if there
  is no brain activity?
• Death is a process not an event
• Physiologists when the heart stops beating, the
  cells begin to die
• O2 levels drop
• Basic processes of the body fails
• Nerves, muscles, organs stop working, Stoppage
• Once enough cellular death occurs life cannot
  restart

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Forensic Pathologist

• Examination of the deceased, Autopsy
• Necropsy
• Investigations normally are called upon when the
  death is
• Sudden
• violent
• unexplained deaths
• Will Investigate
• Manner
• Cause
• And mechanism of death
• of Usually preformed by a coroner/medical
  examiner
• Questions sought to answer
• Who is the victim
• What injuries are present
• When did the injuries occur
• Why and how were the injuries produced

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Forensic Pathology

• Autopsy performed to establish cause of death.
• Classifications the manner of Death
• Natural
• Homicide
• Suicide
• Accident
• Undetermined

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Manner of Death

• Five ways people die
• Natural
• Interruption and failure of bodily function
  resulting from age or disease
• Accidental
• Unplanned event
• Suicidal
• A person purposely kills oneself
• Homicidal
• Death of one person caused by another
• Undetermined
• Suicidal or accidental
• Pills, guns

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Do Now Identify what is the Manner of Death?

• Case 1 A man with a heart condition is
  attacked and dies from a heart attack during the
  assault.
• Case 2 An elderly woman dies after being kept
  from receiving proper health care by her son.

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Types of Death???

• Manner of Death,
• Natural, Accidental, Suicidal, Homicidal,
  Undetermined
• Cause of death The reason someone dies
• Disease physical injury, stroke, heart attack
• bludgeoning, shooting, hanging suffocation,
• Mechanism of Death the specific change in the
  body that brought about the cessation of life
• exsanguinations (Blood loss)
• Pulmonary arrest (Heart stoppage)

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Cause and Mechanism of Death

• Cause of death The reason someone dies
• Disease physical injury, stroke, heart attack
• Homicidal bludgeoning, shooting, hanging
  suffocation,
• Mechanism of Death the specific change in the
  body that brought about the cessation of life
• exsanguinations (Blood loss)
• Pulmonary arrest (Heart stoppage)

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Please provide the Manner, Cause and Mechanism of
Death for John Locke.

• Remember the season finale, he was hung.
• Manner of Death
• Cause of death
• Mechanism of Death

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Please provide the Manner, Cause and Mechanism of
Death for John Locke.

• Manner of Death Homicide
• Cause of death hanging suffocation, (asphyxia)
• Mechanism of Death hypoxia,
• reduction of oxygen supply to a tissue

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Time of Death

• Livor Mortis
• Rigor Mortis
• Algo Mortis

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HomeworkResearch and Identify How investigators
estimate time of death..There are about 9 ways
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Estimating Time of Death

• 9 Ways of Estimating Actual Time of Death

1. Rigor mortis
2. Livor mortis (Lividity)
3. Algor mortis Body Core Temperature
4. Potassium levels in vitreous humor Clouding of
   the cornea
5. Stomach Contents
6. Evidence of Decompositional Process
7. Presence/absence of purge fluids
8. Drying of the tissue
9. Insect Larval Instars

http//www.dundee.ac.uk/forensicmedicine/llb/timed
eath.htmTime20of20Death
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Algor Mortis
1. Algor mortis
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1. Algor mortis (L algorcoolness ath)

• the reduction in body temperature following
  death.
• a steady decline until matching ambient
  temperature
• A measured rectal temperature can give some
  indication of the time of death.
• Newton's law of cooling states that the rate of
  cooling of a body is determined by the difference
  between the temperature of the body and that of
  its environment.
• The Glaister equation 1-1 1/2 degree F per hour
• Algor mortis is usually the first sign of death,
  beyond the obvious, and is then followed by rigor
  mortis. As decomposition occurs the internal body
  temperature tends to rise again. WHY?????

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Questions What are some Factors that would
affect Algor Mortis?

• Ambient temperature
• Wind?
• Excess body fat?
• Clothing
• etc

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2. Rigor Mortis

• (L rig- stiff mortisdeath)
• Muscles become rigid
• Starts w/I 2 hours but gone after 48 hours
• After 48 hours muscles begin to autolysis
  (dissolve)
• The biochemical cause of rigor mortis is
  hydrolysis of ATP in the muscle tissue, the
  chemical energy source required for movement.
  Myosin molecules devoid of ATP become permanently
  adherent to actin filaments and muscles become
  rigid.

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2. Rigor Mortis
Time Event Appearance
2-6 hours Rigor begins eyelids, Jaws stiffen
After 2 hours then center of body stiffens
12 hours Complete Rigor Entire body rigid
15-36 Slow loss of rigor, small muscles first Lost in head and neck, last is bigger leg muscles
36-48 Rigor disappears, muscles become relaxed
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2. What are some factors affecting Rigor mortis ?

• Ambient temperature,
• Cooler the body the slower to onset of rigor
• Persons weight
• fat stores more oxygen and slow rigor
• Type of clothing
• Helps keep the body warm
• Illness
• Dies with a fever? What would you expect?
• Hypothermic? What would you expect?
• Level of physical activity
• Struggling before death rigor, What would you
  expect?
• Sun exposure,
• Sun tanner? What would you expect?

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Live muscles fiber slide back and forth in 48
hours after death, the muscles become locked in a
fixed position
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3. Livor mortis
or (postmortem lividity) L liv-bluish)
Is a settling of the blood in the lower portion
of the body Causing a purplish red
discoloration of the skin. Discoloration
does not occur in the areas of the body that are
in contact with the ground or another object,

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3. Livor mortis
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Special thanks to

• http//classjump.com/dizengoff/documents/692965264
  6.pdf

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4. Rate of Decay
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4. Rate of Decay
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5. Stomach Contents
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6. Entomology
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6. Entimology
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Blow Fly Life cycle
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Total time 16 to 35
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6. Entomology Flies
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Total time 16 to 35
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6. Entomology Beetles
The American carrion beetle, Necrophila
americana.  Although this beetle is primarily
nocturnal, it is commonly observed on the upper
surfaces of a body during the daylight hours. 
Large aggregations of these beetles have been
observed, and they can sometimes be as numerous
as flies.  
The sexton beetle, Nicrophorus orbicollis.  The
sexton beetles are generally nocturnal and are
typically found under a body or in the soil
immediately surrounding the remains during the
daylight hours. 
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7. Potassium levels in Vitreous humor and
clouding cornea
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8. Presence/absence of purge fluids9. Drying of
the tissue
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Stages of Decomposition

• Initial decay
• Corpse appears normal, internal bacterial decay
  and autolysis begins
• Putrefaction
• Odor of decaying corpse swollen
• Black Putrefaction
• Very strong odor, flesh appears black, gases
  escape, corpse collapses
• Dry Decay
• Corpse is almost dry, further decay slows from
  lack of moisture

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Guess the Stage of Decomposition
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Stages of Decomposition

• 2 days
• Cells autolysis
• Greenish purple staining occurs, blood
  decomposing
• Skin takes on Marbled Appearance
• 4 days
• Skin blisters
• Abdomen swells with carbon dioxide
• Due to bacteria in intestines
• 6-10 days
• Corpse bloats with CO2
• Corpse eventually bursts
• Fluid begins leaking from openings as cell
  membranes rupture
• Eyeballs liquefy
• Skin sloughs off

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The-