Transcript Forensic Pathology and Autopsy

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Field of Medicine concerned with identifying
disease
Forensic Pathology – subspecialty of pathology
concerned with identification of human
remains and determination of the cause and
manner of death
The Field that performs an after death
investigation of sudden or unexpected death or
injury
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Deaths with violence – accidents, suicides,
homicides
Suspicious Deaths
Sudden, unexpected deaths,
Deaths without a physician in attendance
Deaths in a prison or jail
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Identify:
Cause – The event/ injury that starts the process
towards death
 Manner  Mechanism – the normal body function that results
in death
 Whether Time of death is consistent with proposed
time
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Formerly not a problem
End of heart and/or lung function
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No oxygen or blood = no life
Brain death
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Individuals may be kept alive by artificial means
through machines that breathe as lungs would or
that pump as a heart would
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The process that starts the chain of events
leading to death
Atherosclerosis  Heart Attack
 GSW to Chest  infection of lungs
 Car Accident  death during surgery 10 years later
 Blunt Force injury to head  not swallowing
correctly  Choke
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Natural
Accident
Suicide
Homicide
Undetermined
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Atherosclerosis
Pneumonia
Cancer
Long term Alcohol/Drug abuse
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Car Accident
Alcohol/ Drug overdose
Drowning
Suffocation
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GSW
Stab Wound
Drug Overdose
Drowning
Car Accident
Asphyxia
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Not enough information about circumstances
surrounding death
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Drug overdose – accidental overmedication or
suicide
Cause of death unknown
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Skeletonized remains
No anatomical or toxicological explanation
Medical and legal conclusions rely on thorough
scene investigation
 Identity
 Approximate time of death
 Evidence and clues to circumstances around
death
Was the house locked?
 Were there signs of struggle
 Position of body
 Suicide notes
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Visual by family/friends
Location of body – in their home?
ID – driver’s license, distinctive feature – tattoo
Comparing x-rays
Dental Records
DNA
Fingerprints
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The immediate activity that results in death.
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Hemorrhage
Widespread infection
Heart Attack
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Important for time of the murder, eliminate or
suggest suspects, confirm or disprove alibi
Most methods are to a degree unreliable and
inaccurate.
The longer the time between death and the
attempt to estimate the time of death, the less
precise the estimate of the interval
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Body temperature – 98.6 – rectal temp /1.5
Insect action
Stomach contents – stage of digestion
Last known activity – newspaper/ mail, phone
conversation/ text
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Livor Mortis is a reddish/ purple coloration due to
accumulation of blood in the small vessels of the
gravity dependent areas.
Occurs 30 min to 2 h after death
 Fixed at 8-12 h
 Important to determine position of body
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Rigor – stiffening of the body due to disappearance
of muscle energy
Usually appears 2-4h after death, fully develops 6-12 h
after death
 Classically
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 Jaw arms -> legs
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Body Temperature
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Time since death = (98.6°F – Rectal Temp) / 1.5
Based on assumption body temp is normal at death
Decomposition (Decomp)
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Breakdown of Cells and Organs by chemical process
Breakdown by bacteria and fermentation
Green discoloration of abdomen (24-36h)
Green spreads to head, neck and shoulders
Swelling of the face and abdomen due to gas formation
Marbling – breakdown of blood gives green/black color of
blood vessels
Generalized bloating (60-72 h)
Skin slippage
Dry/ skeleton phase – 2 weeks in hot humid temps, months in
snow
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Different insects are attracted at different stages
after death
Flies are the most common form of insect
associated with dead bodies
Lay eggs in orifices and open wounds
Eggs generally are deposited immediately after
death in the day time
Only eggs on the body = 1-2 days
Maggots grow excessively larger in different
stages each about 1 day
Adult flies emerge at 12 -18 days
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General Size and Appearance
Clothing /personal belongings
Major Injuries – cause of death signs
Medical Intervention
Signs of struggle – Frenulum, broken bones,
scratches around the hands
Bruises, cuts, petechiae
Scars, tattoos
Livor, Rigor
Teeth, eyes, hair
Blood, eye fluid, urine
Trauma to the Human Body
1. Determine type of wound
2. Measure the dimensions (length, width,
depth)
3. Position relative to anatomical landmarks
4. Determine initial location if wound involves
cutting, slashing, etc.
5. Determine height from heel
Types of Wounds
1. Lacerations
2. Incised Wound
3. Puncture
4. Abrasion
5. Contusion
6. Gunshot
Laceration
s
Incised Wounds
Slash
Stab
Puncture – penetrating injury due to an object with no blade
Abrasions
Contusions
Color changes a bruise goes
through can give rough
estimate of time of injury
• Dark blue/purple (1-18 hours)
•Blue/brown (~1 to 2days)
•Green (~ 2 to 3 days)
•Yellow (~3 to 7 days)
Assumes person is healthy.
Gunshot Wounds
Things for pathologist to learn:
• type of firearm
• distance of gun to victim
• entrance vs exit wounds
• track of projectile
Gunshot Wounds
Starring of a
contact wound –
barrel touching the
skin
Stippling – powder burns on
the skin when the gun is
inches to a few feet from the
victim
Autops
y
Y incision
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Y Shaped insicision
Remove Sternum
Exam any signs of injury internally (gunshot
hole, stab wound)
Exam for signs of blood inside
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Exam each organ, weigh them, cut them open,
take pieces for microscope exam
Heart
Lungs
Kidneys
Liver
Spleen
Bladder
Brain
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Heart Attack
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Contact
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Close Range
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Increased diameter of soot of tattooing around wound
Particles of gunpowder around wound, soot on skin, tattooing
of skin
Intermediate
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Muzzle imprint, star-like cuts if close to bone, gunpowder and
soot enter wound
Up to 3 feet
Increase in diameter again of particles and stippling, no soot
Long Range
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No gunpowder, soot, tattoing
Difficult to determine distance –6 feet not different from 16 feet
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Entrance Wounds
Usually smaller than exit wounds
 May have star-like appearance
 Inward beveling of skull
 Ring of gunpowder and stippling
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Exit wounds
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Usually larger than entrance due to deflection by
tissue
Outward beveling
No gunpowder, soot or skin injury
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Anything that interferes with oxygen uptake or
utilization
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Suffocation
 Failure of oxygen to reach blood
 Choking, drowning, carbon monoxide poisoing
 Compression of chest – heavy objects
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Strangulation
 Usually cuts off blood supply to brain, not cutting off
air.
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Death due to smoke inhalation, incineration or
infection
Establish – ID, whether the victim was alive at
the time of fire
Cause of death
Manner of death
75% of fire related deaths due to inhalation of
toxic smoke – carbon monoxide, cyanide
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Low voltage
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Burns present at entry and exit sites
Death due to heart attack
High Voltage
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Electrical burns
Charring
Death due to hearth attack or paralysis of breathing
muscles
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Brain Contusion – coup occurs at site of blow
to head
Bleeding under skull and into brain
Tearing of arteries and veins that supply the
brain
May kill immediately, or have slow growth of
blood in the brain that compresses brain and
prevents brain function
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Patterned abrasions / bruises from steering
wheel and seatbelt
Damage to liver and spleen