Death Investigation

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Death Investigation
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Summary

• Cause and Mechanism of Death
• Mechanical trauma (gunshot, stabbing)
• Chemical trauma (overdose, poison)
• Other

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• K-Fed sez
• Quiz on Friday.

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Death Investigation

• Cause of death disease or injury that initiated
  the events that led to death

Mechanism of death Physical abnormality produced
by cause of death that is incompatible with life.
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Death Investigation
Examples

• Richard Moll has purloined Marsha Warfields sack
  lunch from the set of Night Court 2010.

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Death Investigation
Examples

• Richard Moll has purloined Marsha Warfields sack
  lunch from the set of Night Court 2010. Marsha
  smothers him with a pillow. Richard Moll dies.

Mechanism of death asphyxia
Cause of death smothering
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Death Investigation
Examples

• William Blake has set Siegfried and Roys tiger
  on fire. Siegfried stabs him in the aorta. The
  ambulance gets into an accident on the way to the
  hospital. Blake dies.

Mechanism of death loss of blood
Cause of death stabbing
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Death Investigation
Examples

• Man shot during robbery. Man stabilizes.
  Develops pnemonia. Followed by kidney failure,
  liver failure, heart failure, death. Had prior
  lung and heart disease, and probably would have
  survived if not for these diseases.

Mechanism of death heart failure
Cause of death gun shot
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Death Investigation

• Determining the manner of death

• Natural
• Accidental

• Homicidal
• Suicidal

For example, a gunshot could be three of the
above choices.
Manner may be undetermined.
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Death Investigation

• Classification of Traumatic Deaths

• Mechanical
• Thermal

• Chemical
• Electrical

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Death Investigation gt Traumatic Death

• Mechanical

• Sharp force (knife)
• Blunt force (gunshot, baseball bat, etc.)

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Death Investigation gt Traumatic Death

• Mechanical (sharp force vs. blunt force)

• Sharp force
• Sharp edges
• Incised wound

• Blunt force
• Rough edges
• Laceration

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Death Investigation gt Traumatic Death

• Mechanical (sharp force)

• Difficult to determine size of blade from size of
  wound

• Smaller/larger blade may cause larger/smaller
  wound

Mechanism of death usually loss of blood
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Death Investigation gt Traumatic Death

• Mechanical (blunt force - firearms)

• Most common homicidal suicidal wound in US

• Damage due more to velocity than mass

Wounds can be

• Penetrating entrance wound, no exit wound
• Perforating entrance and exit wound

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Death Investigation gt Traumatic Death

• Mechanical (blunt force - firearms)

Escaping gases may affect appearance of wound
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Death Investigation gt Traumatic Death gt
Mechanical gt Firearm Wound

• Contact or near-contact wound

• Gases burn (blacken) skin
• Gases into wound tears skin (blown out
  appearance)
• Possible head explosion

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Death Investigation gt Traumatic Death gt
Mechanical gt Firearm Wound

• Intermediate range wound

Unburned powder creates stippling around wound.
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Death Investigation gt Traumatic Death gt
Mechanical gt Firearm Wound

• Distance gunshot wound

• Circular hole with rim of abraded skin.
• Note size of bullet cannot be determined

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Death Investigation gt Traumatic Death gt
Mechanical gt Firearm Wound

• Entrance vs. Exit wound

• Typically, entrance wound smaller than exit
  wound.
• Reason nothing behind exit wound to prevent
  explosive burst.

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Death Investigation gt Traumatic Death gt
Mechanical gt Firearm Wound

• Entrance vs. Exit wound

• Exception is if exit wound is shored. Tight
  fabrics or body against object prevents the
  explosive outburst.
• Shored exit wound looks like entrance wound
  (which is always shored by body)

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Death Investigation gt Traumatic Death gt
Mechanical gt Firearm Wound

• Damage relates to kinetic energy

• Exiting bullet wastes kinetic energy
• Hollow point bullets designed to expand and stay
  in body longer in reality not much difference.

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Death Investigation gt Traumatic Death gt
Mechanical gt Firearm Wound

• Damage due to rebounding tissue

• Bullet too fast to tear tissue pushes tissue
  aside creating cavity.
• Tissue tears upon rebound, along with some
  surrounding tissue.
• Damage about 3x diameter of bullet

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Death Investigation gt Traumatic Death

• Mechanical (blunt force non-firearms)

• Most common are car accidents
• For homicide (beatings) almost always involves a
  blow to the head.

Mechanism of death usually drowning in blood
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Death Investigation gt Traumatic Death

• Mechanical (blunt force non-firearms)

• Rarely will one blow to the head knock a person
  unconscious.

• Book fails to mention vulcans.

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Death Investigation gt Traumatic Death

• Mechanical (blunt force non-firearms)

Contusion accumulated blood in tissues outside
the blood vessels (internal bleed)
Hematoma large contusions (blood tumor) goose
egg on head
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Death Investigation gt Traumatic Death

• Chemical Trauma

• Overdoses depressants (including alcohol) slow
  communications. Can cause coma.

• Stimulants may cause seizures and death, less
  common.

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Death Investigation gt Traumatic Death

• Chemical Trauma

• Carbon Monoxide binds hemoglobin, blocks oxygen.
  Kills by asphyxiation.

• Other poisons interfere with a variety of
  essential biological functions.

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Death Investigation gt Traumatic Death

• Thermal Trauma

Hypothermia excessive cold Hyperthermia
excessive heat

• Both hard to diagnose

• Death from fire usually due to carbon monoxide
  poisoning.

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Death Investigation gt Traumatic Death

• Electrical Trauma

• Heartbeat relies on electrical signals from the
  brain.

• Low voltage causes heart to quiver, then stop.

• Extremely high voltage causes heart to contract,
  then start beating again.