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.

Examples: Death Investigation Richard Moll has purloined Marsha Warfield’s sack lunch from the set of Night Court 2010.

Examples: Mechanism of death: asphyxia Cause of death: smothering Death Investigation Examples: 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. Mechanism of death: asphyxia Cause of death: smothering

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

Examples: Mechanism of death: heart failure Cause of death: gun shot 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

Determining the manner of death: 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.

Classification of Traumatic Deaths: Death Investigation Classification of Traumatic Deaths: Mechanical Thermal Chemical Electrical

Mechanical Sharp force (knife) Death Investigation > Traumatic Death Mechanical Sharp force (knife) Blunt force (gunshot, baseball bat, etc.)

Mechanical (sharp force vs. blunt force) Death Investigation > Traumatic Death Mechanical (sharp force vs. blunt force) Sharp force Sharp edges Incised wound Blunt force Rough edges Laceration

Mechanism of death usually loss of blood 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

Mechanical (blunt force - firearms) Death Investigation > 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

Mechanical (blunt force - firearms) Death Investigation > Traumatic Death Mechanical (blunt force - firearms) Escaping gases may affect appearance of wound

Contact or near-contact wound Death Investigation > Traumatic Death > Mechanical > Firearm Wound Contact or near-contact wound Gases burn (blacken) skin Gases into wound tears skin (blown out appearance) Possible head explosion

Intermediate range wound Death Investigation > Traumatic Death > Mechanical > Firearm Wound Intermediate range wound Unburned powder creates stippling around wound.

Distance gunshot 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)

Damage relates to kinetic energy 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.

Damage due to rebounding tissue 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

Mechanical (blunt force – non-firearms) Death Investigation > 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

Mechanical (blunt force – non-firearms) 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.

Mechanical (blunt force – non-firearms) 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.

Thermal Trauma Hypothermia: excessive cold Death Investigation > Traumatic Death Thermal Trauma Hypothermia: excessive cold Hyperthermia: excessive heat Both hard to diagnose Death from fire usually due to carbon monoxide poisoning.

Death Investigation > 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.