Death Investigation

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

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.

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

Entrance vs. Exit wound  Typically, entrance wound is 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

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) 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