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Death Investigation
Summary
Cause and Mechanism of Death Mechanical trauma (gunshot, stabbing) Chemical trauma (overdose, poison) Other
K-Fed sez:
Quiz on Friday.
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.
Richard Moll has purloined Marsha Warfield’s sack lunch from the set of Night Court 2010.
Examples:
Death Investigation
Richard Moll has purloined Marsha Warfield’s sack lunch from the set of Night Court 2010. Marsha smothers him with a pillow. Richard Moll dies.
Cause of death: smothering
Mechanism of death: asphyxia
Examples:
Death Investigation
William Blake has set Siegfried and Roy’s tiger on fire. Siegfried stabs him in the aorta. The ambulance gets into an accident on the way to the hospital. Blake dies.
Cause of death: stabbing
Mechanism of death: loss of blood
Examples:
Death Investigation
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.
Cause of death: gun shot
Mechanism of death: heart failure
Examples:
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.
Death Investigation
Classification of Traumatic Deaths:
Mechanical Thermal
Chemical Electrical
Death Investigation
Mechanical
Sharp force (knife) Blunt force (gunshot, baseball bat, etc.)
Death Investigation > Traumatic Death
Mechanical (sharp force vs. blunt force)
Sharp force Sharp edges Incised wound
Blunt force Rough edges Laceration
Death Investigation > 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
Death Investigation > Traumatic Death
Mechanical (blunt force - firearms)
Most common homicidal & suicidal wound in US
Wounds can be:
Damage due more to velocity than mass
Penetrating: entrance wound, no exit wound Perforating: entrance and exit wound
Death Investigation > Traumatic Death
Mechanical (blunt force - firearms)
Escaping gases may affect appearance of wound
Death Investigation > Traumatic Death
Contact or near-contact wound
Gases burn (blacken) skin Gases into wound tears skin
(blown out appearance) Possible head explosion
Death Investigation > Traumatic Death > Mechanical > Firearm Wound
Intermediate range wound
Unburned powder creates stippling around wound.
Death Investigation > Traumatic Death > Mechanical > Firearm Wound
Distance gunshot wound
Circular hole with rim of abraded skin. Note: size of bullet cannot be determined
Death Investigation > Traumatic Death > Mechanical > Firearm Wound
Entrance vs. Exit wound
Typically, entrance wound smaller than exit wound.
Reason: nothing behind exit wound to prevent explosive burst.
Death Investigation > Traumatic Death > Mechanical > 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)
Death Investigation > Traumatic Death > Mechanical > 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.
Death Investigation > Traumatic Death > Mechanical > 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
Death Investigation > Traumatic Death > Mechanical > Firearm Wound
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
Death Investigation > Traumatic Death
Mechanical (blunt force – non-firearms)
Rarely will one blow to the head knock a person unconscious.
Book fails to mention vulcans.
Death Investigation > 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
Death Investigation > Traumatic Death
Chemical Trauma
Overdoses: depressants (including alcohol) slow communications. Can cause coma.
Stimulants may cause seizures and death, less common.
Death Investigation > Traumatic Death
Chemical Trauma
Carbon Monoxide: binds hemoglobin, blocks oxygen. Kills by asphyxiation.
Other poisons interfere with a variety of essential biological functions.
Death Investigation > Traumatic Death
Thermal Trauma
Hypothermia: excessive cold
Hyperthermia: excessive heat
Death from fire usually due to carbon monoxide poisoning.
Death Investigation > Traumatic Death
Both hard to diagnose
Electrical Trauma
Heartbeat relies on electrical signals from the brain.
Extremely high voltage causes heart to contract, then start beating again.
Low voltage causes heart to “quiver”, then stop.
Death Investigation > Traumatic Death