FORENSIC PATHOLOGY AND AUTOPSY
Pathology 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
What Do They See Deaths with violence – accidents,
suicides, homicides Suspicious Deaths Sudden, unexpected deaths, Deaths without a physician in attendance Deaths in a prison or jail
Goals 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
Definition of Death Formerly not a problem End of heart and/or lung function
No oxygen or blood = no life Brain death
Individuals may be kept alive by artificial means through machines that breathe as lungs would or that pump as a heart would
Cause of Death 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
Manner of Death Natural Accident Suicide Homicide Undetermined
Natural Deaths Atherosclerosis Pneumonia Cancer Long term Alcohol/Drug abuse
Accident Car Accident Alcohol/ Drug overdose Drowning Suffocation
Homicide/Suicide GSW Stab Wound Drug Overdose Drowning Car Accident Asphyxia
Undetermined Not enough information about
circumstances surrounding death Drug overdose – accidental overmedication or
suicide Cause of death unknown
Skeletonized remains No anatomical or toxicological explanation
Scene investigationMedical 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
Identification of remains Visual by family/friends Location of body – in their home? ID – driver’s license, distinctive feature –
tattoo Comparing x-rays Dental Records DNA Fingerprints
Mechanism of Death The immediate activity that results in
death. Hemorrhage Widespread infection Heart Attack
Time of Death 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
Estimation methods Body temperature – 98.6 – rectal temp
/1.5 Insect action Stomach contents – stage of digestion Last known activity – newspaper/ mail,
phone conversation/ text
Livor and Rigor 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
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
Jaw arms -> legs
Time of Death Body Temperature
Time since death = (98.6°F – Rectal Temp) / 1.5 Based on assumption body temp is normal at death
Decomposition (Decomp) Breakdown of Cells and Organs by chemical process Breakdown by bacteria and fermentation
1. Green discoloration of abdomen (24-36h)2. Green spreads to head, neck and shoulders3. Swelling of the face and abdomen due to gas formation4. Marbling – breakdown of blood gives green/black color of blood
vessels5. Generalized bloating (60-72 h)6. Skin slippage7. Dry/ skeleton phase – 2 weeks in hot humid temps, months in
snow
Entomology 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
External Exam 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
Abrasions
ContusionsColor 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
Autopsy
Y incision
Internal Exam Y Shaped insicision Remove Sternum Exam any signs of injury internally
(gunshot hole, stab wound) Exam for signs of blood inside
Organs Exam each organ, weigh them, cut them
open, take pieces for microscope exam
Heart Lungs Kidneys Liver Spleen Bladder Brain
Natural Deaths Heart Attack
Gunshot Wounds Contact
Muzzle imprint, star-like cuts if close to bone, gunpowder and soot enter wound
Close Range Increased diameter of soot of tattooing around wound Particles of gunpowder around wound, soot on skin, tattooing
of skin Intermediate
Up to 3 feet Increase in diameter again of particles and stippling, no soot
Long Range No gunpowder, soot, tattoing Difficult to determine distance –6 feet not different from 16
feet
GSW Entrance Wounds
Usually smaller than exit wounds May have star-like appearance Inward beveling of skull Ring of gunpowder and stippling
Exit wounds Usually larger than entrance due to deflection
by tissue Outward beveling No gunpowder, soot or skin injury
Asphyxia Anything that interferes with oxygen
uptake or utilization Suffocation
Failure of oxygen to reach blood Choking, drowning, carbon monoxide poisoing Compression of chest – heavy objects
Strangulation Usually cuts off blood supply to brain, not cutting
off air.
Burns 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
Electrocution Low voltage
Burns present at entry and exit sites Death due to heart attack
High Voltage Electrical burns Charring Death due to hearth attack or paralysis of
breathing muscles
Blunt force injury to head 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
Car Accident Patterned abrasions / bruises from
steering wheel and seatbelt Damage to liver and spleen