Forensic Pathology Final

Forensic pathology

Medical specialty that determines how and why someone died

Forensic pathologist

Doctor who performs autopsies and determines cause/manner of death

Medical examiner (ME)

Physician who investigates deaths and performs autopsies

Coroner

Elected official who investigates deaths; may not be medically trained

Goal of forensic pathology

To determine cause

Cause of death

The injury/disease/event that starts the chain leading to death

Mechanism of death

The body failure that actually caused death (ex: blood loss)

Manner of death

How the death happened (natural

Natural death

Death due to disease or internal body malfunction

Accidental death

Unintentional cause of death (fall

Suicide

Death caused by a person’s own intentional action

Homicide

Death caused by another person

Undetermined

Not enough information to classify death

Autopsy

Medical examination of the body after death

Hospital autopsy

Autopsy requiring family consent for medical/teaching purposes

Forensic autopsy

Autopsy ordered by law for suspicious or violent deaths

Who reports deaths

Hospitals police nursing homes hospice fire department prisons

Scene investigation

Examining where the body was found for clues

Why scene matters

Explains injuries and helps estimate time and circumstances of death

Chain of custody

Documentation tracking evidence handling

Importance of chain of custody

Keeps evidence reliable and valid in court

Body identification

Process of determining who the deceased is

Identification methods

Fingerprints dental records DNA implants tattoos

Unknown body

Body without immediate identification

External exam

Visual inspection of outside of body for injuries

Internal exam

Opening the body to examine organs

Autopsy technician

Assistant handling body prep and tools

Pathologist assistant

Highly trained examiner helping perform autopsy procedures

Autopsy report

Written explanation of autopsy findings

Postmortem interval (PMI)

Time since death occurred

PMI accuracy

Always an estimate not exact

Livor mortis

Blood pooling in lowest parts of body after death

Livor start

30 minutes to 2 hours after death

Livor fixed

8 to 12 hours after death

Lividity use

Shows if body was moved

Rigor mortis

Stiffening of body muscles after death

Rigor start

3 to 6 hours after death

Rigor full

12 hours after death

Rigor ends

24 to 36 hours after death

Factors speeding rigor

Heat exercise seizures infection

Factors slowing rigor

Cold thin body chronic disease

Algor mortis

Body cooling after death

Body temperature PMI rule

37°C minus body temp plus 3 hours

Decomposition

Process of body breaking down

Fresh stage

Immediately after death with no major changes

Bloat stage

Gas causes swelling and discoloration

Active decay

Strong odor maggots feed tissues break down

Advanced decay

Body collapses dries out

Skeletonization

Only bones remain

Marbling

Green/black vein pattern on skin

Skin slippage

Skin peels away due to decomposition

Adipocere

Wax-like fat formation in wet environments

Mummification

Body dries out in hot/dry environment

Insect activity

Used to estimate how long body has been dead

Blowflies

First insects to colonize body

Maggots

Larvae feeding on decomposing tissue

Blunt force trauma

Injury from non-sharp object impact

Abrasions

Scrapes where top skin layer is removed

Patterned abrasion

Abrasion shaped like the object that caused it

Contusion

Bruise from bleeding under skin

Laceration

Jagged tear of skin caused by blunt force

Tissue bridging

Strands that remain intact in lacerations

Fracture

Broken bone

Depressed skull fracture

Indented skull fracture

Linear skull fracture

Straight-line skull break

Sharp force trauma

Injury caused by knives or sharp objects

Incised wound

Longer than it is deep clean smooth edges

Stab wound

Deeper than it is long caused by pointed object

Chop wound

Deep wound from heavy sharp weapon

Hesitation marks

Shallow repeated cuts in suicide attempts

Defensive wounds

Injuries from trying to block attack

Gunshot wound

Injury caused by bullet entering body

Entrance wound

Small round abrasion ring sometimes soot

Exit wound

Irregular larger no soot

Soot

Black residue from close-range gunshot

Stippling

Pinpoint gunpowder dots that can’t be wiped away

Contact GSW

Gun pressed directly to skin soot enters wound

Near contact GSW

Some soot but slight distance

Intermediate GSW

Stippling present

Distant GSW

No soot no stippling

Internal beveling

Entrance wound characteristic in skull

External beveling

Exit wound characteristic in skull

Temporary cavity

Stretching of tissue from bullet energy

Permanent cavity

Actual physical bullet track

Shored exit wound

Abrasion around exit caused by object supporting skin

Explosion

Rapid energy release causing blast injury

Low-order explosion

Subsonic explosion like gasoline vapor

High-order explosion

Supersonic shock wave like bombs

Primary blast injury

Damage from pressure wave (lungs ears)

Secondary blast injury

Injuries from flying debris

Tertiary blast injury

Body thrown causes blunt trauma

Quaternary blast injury

Burns chemicals inhalation injuries

Blast lung

Lung damage from pressure wave

Electrocution

Death or injury from electricity

Electrical burn

Entry/exit burn marks

Lichtenberg figures

Tree-like lightning burn patterns

Drowning

Death from inability to breathe underwater

Foam cone

Foam around nose/mouth in drowning or overdose

Carboxyhemoglobin

CO bound to hemoglobin

Cherry-red skin

Sign of carbon monoxide poisoning