THE FORENSIC PATHOLOGIST The forensic pathologist performs autopsies to determine the cause and mechanism of violent deaths such as homicides, accidents,

THE FORENSIC PATHOLOGIST

The forensic pathologist performs autopsies to determine the cause and mechanism of violent deaths such as homicides, accidents, and suicides.

He must determine three important things:

cause of death: mechanism of death: time of death

Forensic pathologists are often called upon as an expert witness

CAUSE v. MECHANISM OF DEATH

• Cause of death is a specific medical diagnoses: – Asphyxiation– Exsanguination

• Mechanism of death: – drowning, strangle– Multiple stab wounds

TIME OF DEATH

Factors such as

indicative acts,

postmortem body temperature (algor mortis),

postmortem lividity (livor mortis),

stiffening of the body (rigor mortis),

and putrefaction can all help to roughly estimate the time of death.

Entomological studies

Exam stomach contents

Rigor mortis occurs when the body (the muscles) stiffens after death.

Putrefaction destruction of tissues by bacteria and enzymes : dissolution of tissue into gases, liquids.

Entomological studies estimate stage of life of insects that inhabit the body

Algor mortis

• Cooling of the body after death.

• Best indicator of TOD in 1st 24 hrs

Algor Mortis

• Body cools approx 1.5 degrees C/hr– Skinny cools faster– No clothes cools faster– In water cools much faster

• normal temp – measured temp/ 1.5 = #of hrs

Livor Mortis

• Lividity: red/purple coloration of skin.

• Due to settling of blood after death

• Skin will appear white in areas that were compressed.

Livor Mortis

• Lividity will appear in about 2 hours.– Areas will turn

white if you press

• Lividity will be “set” after 5 hours

Rigor Mortis

• Rigor: stiffening of muscles due to build up of salts.

Rigor mortis

• Rigor – Begins: 12 hours post mortem– face, arms, abdomen, legs– Takes: 12 hours to get fully stiffened– Then starts to go away in same order

• Face, arms, abdomen, legs

Decomposition

• 2 days post mortem– Marbling neck and shoulders 1st red then green– From bacteria getting into subQ tissue– Body gets bloated from gases created by bact.– Organs decompose in order:– Stomach and intestines, heart and liver– Lungs, brain, spinal cord– Musculature

ASPHYXIA AND STRANGULATION Insufficient amounts of oxygen reaching

brain or essential organs of bodyCauses of Asphyxiation:Natural: pneumonia, asthma Drowning SmotheringStrangulation: Homicidal, suicidal,

accidental Homicidal strangulation done manually-

brute force choking around neck Homicidal strangulation by ligature using

rope, wire, or garrote Hanging victim dies from pressure of

body weight or neck breaks Intensive heart congestion (enlarged

heart; right side ventricle) Venous engorgement (enlarged veins

above point of injury) Cyanosis (blue discoloration of lips and

fingertips)

BULLET WOUNDS Contact Wound: Muzzle applied to skin at

shooting. Impression of muzzle burned around

entrance wound and absence of fouling and stippling

Close Range (6-8 inches): Entrance surrounded stippling- HOT soot traveling for short distance; BURNS

Intermediate Range (1- 3 ft.): hot fragments of burning gunpowder; “ball”

Distant (greater than 3 ft.): No soot or burning propellant; clean wound margins

Entrance wound: rim of abrasion dragging surrounding skin

Exit wound: projectile penetrates skin and pushes in outward

• Close Range (6-8 inches): Entrance surrounded by stippling- HOT soot traveling for short distance; BURNS

• Intermediate range

• 1-3 feet

STAB WOUNDS Laceration is a tearing injury due to friction or impact with a blunt object. The

typical laceration has edges which are ragged3, bruised, and/or abraded. Puncture is a penetrating injury due to pointed object without a blade, such as

an ice pick The wound edges are smooth. Serrated blades produce the same smooth edges

as do nonserrated blades. Abrasion is a friction injury removing superficial layers of skin, allowing

serum to exude and form a crust. Contusion is a bruise due to rupture or penetration of small-caliber blood

vessel walls. Slash wounds tend to look like bullet wounds that only graze the surface of

the skin. Other types of slash wounds are called "hesitation marks" commonly found in suicide cases. They are typically rectangular in shape; i.e., their cuts are as wide and they are long.

Incision wounds: cutting with a blade, always have lengths greater than their depth, and you'll easily notice that a greater amount of subsurface tissue is exposed in an almost oval fashion.

BURN Scorching or burning of skin leads to sepsis and is

immediate cause of death

Wounds caused by heat, chemicals, or electricity

Fire victims found in “pugilistic” position: clenched fists, resembling pose of boxer

Heat causes protein in body to contract

Blood and lung samples taken

Blunt force trauma

Blunt Force trauma results from clubbing, kicking, or hitting the victims.

The blow produces a crushing effect on the human body, resulting in contusions, abrasions, lacerations, fractures, or rupture of vital organs.

Red-blue contusions are always present, but this varies by the weight of the individual (obese people bruise easier than lean people)

POISONINGDetermined by discolorations on body

Cherry- red lividity is sign of carbon monoxide poisoning

Toxins give off unusual odors

Certainty of diagnosis requires toxicological confirmation

Samples taken of stomach, vomit, kidney, lungs, liver

AUTOPSY OF NICOLE SIMPSON Multiple stab wound

of neck and scalp (total of seven).

Multiple injuries of hands, including incised wound, ring finger of right hand (defense wound).

Scalp bruise, right parietal.

Dr. Lakshamanan Sathyavagiswaran believes Nicole Simpson’s stab wounds were done with a single-edged knife.

Irwin L. Golden, M.D. Deputy Medical Examiner performed an autopsy on Nicole Brown Simpson on June 14, 1994.

Her death was ascribed to multiple sharp force injuries including:

Incised wound of neck: Transection of left and

right common carotid arteries. Incisions, left and right

internal jugular veins Transection of thyrohyoid

membrane, epiglottis, and hypopharynx.

Incision into cervical spine, C3.

AUTOPSY OF RONALD GOLDMAN

His death was ascribed to multiple sharp force injuries including:

Sharp force wound of neck, left side, with transection of left internal jugular vein.

Multiple stab wounds of chest, abdomen, and left thigh: Penetrating stab wounds of chest and abdomen with right hemothorax and hemoperitoneum.

Multiple incised wounds of scalp, face, neck, chest and left hand (defense wound).

Multiple abrasions upper extremities and hands (defense wounds).

Irwin L. Golden, M.D. Deputy Medical Examiner performed an autopsy on Ronald L. Goldman on June 14, 1994.

Dr. Lakshmanan Sathyavagiswaran believes the knife wounds were done with a single-edged knife