Q7: DEATH

FORENSIC PATHOLOGY• Def: Branch of Forensics concerned with determining the cause of death

by the examination of a cadaver

• Cadaver

• Formal term for Dead body

• Medical training and research

• Coroner or Medical Examiner

DEATH

• In the U.S. a person is considered dead by law if a Statement of Death (Death Certificate) is approved by a licensed medical practitioner

• “Possession of brain activity, or capability to resume brain activity, is a necessary condition to legal personhood.”

DEATH• Def: The termination of all biological functions that sustain a living organism.

Phenomena which can bring about death include:

• Senescence (Biological aging)• Malnutrition• Disease• Suicide• Homicide• Starvation• Dehydration• Accidents/Trauma

SENESCENCE• Most animals who survive external hazards will

eventually die from “biological aging”.

• Some animals experience Negligible Senescence or even experience Biological Immortality

NEGLIGIBLE SENESCENCE • Lack of symptoms of aging• No detected increase in mortality rate after maturity• Equally likely to die at any age after maturity

• No measurable reductions in reproductive capabilities

BIOLOGICAL IMMORTALITY• Stable or decreasing rate of mortality

with chronological aging

• Tardigrades

DEATH• The key to Death is STOPPAGE

• Once the Heart stops beating…

• Cells will not receive oxygen. As oxygen levels dropping leads too failure of…

• Nerves

• Muscles

• Organs

• Brain

• Once a cell dies it breaks down. Once enough cells begin to break down life cannot be restarted

AUTOLYSIS

• Autolysis: Cell breakdown

• Cell membrane dissolves

• Enzymes and cell contents spill out into the body

• Enzymes and cell content digest tissue

ROLE OF THE PATHOLOGIST

• Primary role is to determine the Manner of Death. Does this by determining…

• Who is the victim?

• When did the injuries occur?

• Why did the injuries occur?

MANNERS OF DEATH• Officials responsible for investigating death determining

the manner of death

• 5 Manners of Death1. Homicide

• Death of one person caused by another

2. Suicide

• Purposely killing oneself

3. Accidental

• Unplanned event

4. Natural

• Failure of body due to old age/disease

• Most common manner

5. Undetermined

MANNER VS. CAUSE VS. MECHANISM OF DEATH• Manner: the WAY a person can die

• Cause: the REASON someone dies

• Mechanism: the specific CHANGE IN THE BODY.

• Example: Two men have an altercation outside a Las Vegas night club. One man pulls out a gun and shots the other man in the head. He dies• What is the Manner of Death?

• Homicide

• What is the Cause of Death?• Bullet to the head

• What is Mechanism of Death?

• Loss of Blood or Cessation of Brain Function

STAGES OF DECOMPOSITION (5)

• Help to give an estimation of when Time of Death occurred

1. Fresh • Pallor Mortis• Algor Mortis• Rigor Mortis• Livor Mortis

2. Active Decomposition3. Bloated4. Advanced Decomposition5. Dry/Skeletal

PALLOR MORTIS• Post-mortem paleness that occurs within 15-20 minutes of death

• Happens so quickly that it has little to no use in determining time of death

ALGOR MORTIS• Def: Reduction of body temperature following death

• Thermometer is inserted into the Liver• After death cooling rate is 1.4°F per hour• After 12 hours 0.7°F per hour (until ambient temp is reached)• Influenced by

1. Location of body2. Position of body3. Size4. Clothing

– Clothed body of average build loses about 3.5 degrees F in about 6-8 hours

5. Decomposition/maggots6. Cause of death

– Hypothermia– Sepsis (infection/inflammatory)

RIGOR MORTIS• Definition: The relaxation and stiffening of muscles immediately following

death

• Starts 2 hours after death

• Starts at head and works its way down to the legs

• Stiffening rates

• Face 2-4 hours

• Limbs 4-6 hours

• Entire body 12 hours

• Stiffness gradually disappears after 36-48 hours

LIVOR MORTIS• Def: The settling of blood in the body parts closest to the ground

following death due to the heart no longer pumping

• Purplish blue 1-3 hours

• Purplish red 4-6 hours

• Also helps to determine if a body has been moved

PRE-CUT STEPS OF AN AUTOPSY

1. Documenting

• Tape recorders, photos, notes, etc

• Detailed description of the body

• Height, Weight, etc

• Birthmarks, scars, and tattoos

• Underneath fingernails

• Droplets of blood

• Unusual fibers

• Organic material and residues

PRE-CUT AUTOPSY STEPS CONTINUED…

2. Dental Work and X-rays

• Broken or fractured bones

• Injury history

• Medical devices

• Pace Maker

3. Blood Sample

PRE-CUT AUTOPSY STEPS CONTINUED…

4. Swab orifices (openings)

Mouth

Rectum Ted Bundy bite victim

Sexual organs

Bite marks

5. Genital area

• Rape

• Bruising

• Tearing

PRE-CUT AUTOPSY STEPS CONTINUED…

6. Hair is combed (including pubic hair)

7. Looking for signs of asphyxiation Asphyxiation = severe depletion of oxygen to the brain

Signs

• Formation of Petechia

Small dots

Ruptured blood vessels

• Cyanosis

• Bluish color of skin JonBenet Ramsey

AUTOPSY STEPS • Cutting the body

• “Y” incision from each shoulder

• Straight line cut down the chest to belly button

• Check rib cage

• Tupac Shakur

AUTOPSY STEPS• Split rib cage

• Check vital organs

• Weigh

• Tissues samples sent to lab

• Second blood sample directly from heart

• Check stomach

• Partially digested food can be used as evidence

• Repeat process for lower body