Forensic PathologyMedical Examiner

Pathology

Pathology is the study of disease, so forensic pathology is the study of injuries and/or disease in order to determine the cause of death.

Medical Examiner

A medical doctor (MD) who works for the legal system to determine cause of death in legal cases. They conduct autopsies to determine not only the ultimate cause of death but also the manner and mode of death.

Coroner

usually an elected official and does not necessarily have a medical degree. They would oversee the investigation but rely on the information given to them by forensic pathologists to make their decisions.

InvestigationCause (Mode) of Death

The medical or forensic cause:

Gunshot Blunt force trauma Heart Attack Decapitation

Manner of Death

Only 5 Possibilities: Natural Causes Accidental Suicidal Homicidal Undetermined.

Temperature

Normal body temperature is 98.6˚F Body temp of a corpse drops 1.5˚F

every hour A body is cool to the touch after 4-6

hours In 24 hours the body is at external

temperature Several days after death Putrefaction

(bacteria in the body release gases causing body to become bloated) occurs and body temp can rise to 127˚F

Rigor Mortis

Begins ~4 hours after death Stiffening of body because of lack of oxygen in

muscle cells Begins in eyelids and small muscles of jaw,

then to neck and rest of body Is sped up by increased external temp and

slowed down by cooler temp Sets in more slowly with overweight

individuals Sets in more quickly when there has been a

violent struggle (uses up energy in muscles) Completely sets in within 12 hours after death

and lasts ~36 hours before body returns to non-rigid state

Livor Mortis

Discoloration of skin after death Caused by gravity-induced

stagnation and settling of red blood cells in small blood vessels

Commonly referred to as “lividity”

Occurs 6-8 hours after death Occurs in parts of body closest to

ground (gravity!)

Before an autopsy can occur, a medical examiner will search for any physical

evidence on the body:

Conditional evidence – lividity, rigor mortis, odors, insects, position, clothing.

Pattern evidence – bite marks, imprints, impressions, weapon marks, insertions, injuries, wounds

Biological evidence – grass, leaves, wood, plants, pollen, flowers, insects, worms, etc.

Chemical evidence – cosmetics, firearms, vehicle-related chemicals, drugs, alcohol, poisons, ink, oil, cleaning fluids, soil, glass

Physiological evidence – blood, semen, urine, fecal materials, tears, milk, bile, tissues, bone, hair

Autopsy

1. Weight, height, & physical characteristics are documented

2. Body is photographed, x-rayed, and examined with alternate light source (black light) for stains

3. Distinguishing characteristics – tattoos, scars, birthmarks

4. Clips fingernails and toenails for further analysis5. If a rape case, swabs are taken of oral, anal, and

vaginal cavities6. Fingerprints and palm prints7. Y-incision from shoulders down to abdomen8. Saw collarbone and ribs9. Internal organs are all removed, weighed, and

measured10. Blood and tissue samples are taken from each organ11. If necessary, the scalp is peeled back, skull is

opened and brain is examined