1. Forensic Pathology

2. Blunt Trauma Types Contusions Abrasions Lacerations
Black and Blue marks
Abrasions
Scrapes
Lacerations
Split versus cut

3. CUTTING AND STABBING Slicing CUTTING (INCISED) WOUNDS
sharp instrument
longer on the skin surface than it is deep
Edges of the wound are sharp
not usually ragged or abraded
Surrounding skin is usually undamaged.
No tissue bridges
Slicing

4. Stabbing Wounds Deeper than wide The size of skin defect ≠ depth
Ends of the stab wound = angles.
May be blunt or sharp,
Single-edged blade = 1 blunt angle and 1 sharp angle
Double-edge knives = 2 sharp angles
Homemade sharpened weapons = sharp or dull angles.

5. ID of the Weapon Rarely is the weapon discovered in the wound
Matching the weapon to a wound
Tip of the blade breaks off
Can be matched to the weapon

6. Single-edged Knife
Light arrow = blunt angle
Dark arrow = sharp

7. Multiple Incised and Stab Wounds
Defense wounds
Multiple incised and/or stab wounds of the neck, face, and extremities
Usually caused by an assailant
Suicide
Multiple incised wounds of neck, wrists, or leg area
Varying depths on the wound suggest a suicide.
Hesitation marks are characteristic
Overkill
A body sustaining tens or hundreds of stab and incised wounds
Highly emotional setting
Sex
Drugs

8. What Do These Wounds Indicate?

9. Defense Wounds
What type of Wounds?
How were they caused?

10. Some Wounds Can be Caused by Treatment
Lower two wounds were caused by thoracotomy incisions to drain blood from the chest

11. Internal Damage Heart – single-edged blade
Multiple stab wounds in left lung and ribs
10 stab wounds in large incision

12. Head Trauma Contusions, lacerations, and abrasions
Obvious external signs are not necessary
Occasionally, the weapon leaves a characteristic identifying pattern on the scalp
Exception rather than the rule.
Blow to the head → bleeding under the scalp
May be skull fractures
ID weapon or type of instrument

13. Battle’s sign Bluish discoloration of the skin behind the ear
Blood leaking under the scalp after a skull fracture

14. Spectacle hemorrhage
Discoloration of the tissues around one or both eyes
Caused by a fracture of the skull
Can be mistaken for blows to the face and eyes

15. Fell Down the Stairs multiple areas of subscalpular hemorrhage
Series of blows to the head

16. There May be More than One Fracture
Many fractures indicate more than one blow
Need definable points of impact to determine the number of blows

17. Cerebral Contusion Focal brain injury is an injury to:
Region, system, or side of the brain
Most common type of focal brain injury is a cerebral contusion
Bruise in the brain that consists of a superficial focus of brain hemorrhage, necrosis, and/or laceration.

18. Coup contusion Part of the brain receiving the focus of an impact
Contusions and lacerations caused by heavy weapon

19. Contrecoup Contusion
Areas of the brain remote from the focus of impact
Brain bounces off opposite side of skull

20. Cause of Death: Subdural Hemorrhage
Subdural hemorrhage is blood under the Dura
tough membrane that covers the entire brain and spinal cord
It originates from ruptured veins
May not be an associated fracture of the skull.

21. Firearms – Hand Guns and Rifles
Primer – stable, but shock sensitive
Gunpowder or propellant – volumes of gas
Bullet or projectile

22. Gunpowder Soot or fouling tattooing” or “stippling.”
Completely burned gunpowder
can be washed off the skin
tattooing” or “stippling.”
Particles of burning and unburned powder
Become embedded or abrade in the skin

23. What was the Range – Tight Contact
Reddening Due to CO
Muzzle Blow-back
Splitting Due to Gases
All gunpowder residue on the edges or in the wound
Searing or burning of wound margins
Reddening of surrounding skin due to carbon monoxide (CO) gas produced by burning powder
Tearing of the skin around the entrance wound (especially in head wounds)
because of pressure buildup and blow-back of the skin toward the muzzle.

24. Loose contact
Gunpowder deposited around the edges of a wound

25. Close range muzzle-to-target distances of approximately 6–12”
Both fouling and stippling are present
Abundant Soot After washing - Stipling
Powder and Fouling

26. Distant wounds — No fouling or stippling.
Intermediate range
muzzle-to-target distances of approximately 12” to 3’
No fouling, only stippling or deposition of particles on clothing
Distant wounds — No fouling or stippling.

27. Significance of Amount of Gunpowder Present
Different among weapons
Different in same weapon with different ammunition
To make a comparison
Test-fire gun in question
Same ammunition
The scene must be examined for bullets and cartridges.
Bullets may be under the body or caught in clothing after exiting the body.

28. Entrance and Exit Wounds
Entrance wounds
Circular defects with a thin rim of abrasion
Entrance wounds of the face atypical
Surfaces are not flat.
Exit wounds
More often irregular in shape
Slit-like
Ragged edges
No Rim of abrasion unless victim is against another object
shored
Skin around discolored because of underlying bleeding in the soft tissues.
May be circular like entrance wounds

29. Entrance and Exit On the left – Entrance Wound
On the right – Exit Wound
Note beveling
Two Exit Wounds with Hemorrhage
Entrance and Exit Wounds
Shot in chin as going up stairs

31. Shotgun Injuries Different components
Gunpowder
Pellets – sometimes slug
Wad
The range (distance) of fire more easily determined
Presence or absence of pellet spread
Same gun and ammunition

32. Shotgun Wounds Shot by police from across a yard
Three pellets entered the heart

33. ASPHYXIA Asphyxia means death due to lack of oxygen to the brain
Compression of the neck
hanging and strangulation
Blockage of the airway
suffocation, gagging
Compression of the chest, neck, or face
Postural or positional asphyxia
Chemical or lack of available oxygen

34. Compression of the neck
Occlusion of the vasculature in hanging (usually suicide), the neck can be compressed
Not necessarily the airway (larynx or trachea)
Very little pressure is needed
Hanging
Throttleing
Unconscious in seconds
Pressure must be continued in order to cause death.

35. Signs of Trauma to the Neck
Contusions or abrasions, rarely lacerations
Abraded, imprinted mark
Thin ligature – pattern can be matched to the particular ligature
Wide ligature – no specific pattern
Superficial fingernail cuts from either the victim or assailant
Pinpoint hemorrhages, or petechiae (pet-TEA-key-eye)
Eyes, lids, face
buildup of vascular pressure which causes capillaries to rupture
Not often found in suicidal hanging
May occur in sudden natural death
Tardieu spots
Ruptured blood vessels in the tissues after prolonged hanging, especially in the lower extremities,

36. Ligature Marks

37. Petechiae (pet-TEA-key-eye)
Pinpoint hemorrhages
Eyes, lids, face
buildup of vascular pressure which causes capillaries to rupture
Not often found in suicidal hanging
May occur in sudden natural death

38. Tardieu spots
Lower extremities

39. Blockage of the airway Suffocation, aspiration, gagging
Airway is blocked
A pillow or hand placed over the mouth
Un-chewed food or small parts of toys lodged in an infant’s or child’s airway
Individuals without teeth or with a history of stroke or other debilitating disease may have trouble chewing and aspirate food into the airway.
Those under the influence of alcohol are also more likely to aspirate
Usually no signs of trauma

40. Car Fell Off Cement Blocks
Pressure on neck caused
Extreme petechiae
(pet-TEA-key-eye)

41. Postural or Positional Asphyxia
Compression of the chest, neck, or face
person cannot breathe because of an inability to move one’s chest
Airway is compressed against the neck or face
Commonly seen during motor vehicle accidents
when the vehicle overturns on a victim
driver trapped between the steering wheel and seat
Signs of Trauma
Few injuries
Blunt trauma
Petechiae of the eyes and face

42. Alcoholic Fell Asleep with Head on Pillow
His nose and mouth were occluded by the pillow
autopsy showed only signs of alcoholism
Scene investigation was essential
Manner of death - accident

43. Chemical and lack of available oxygen in the atmosphere
O2 is replaced by another chemical or gas
Closed environment
mine shafts, sewers, or chemical storage tanks
Red blood cells are unable to deliver oxygen to bodily tissues
Carbon monoxide
Competes with O2
Cyanide
smells like bitter almonds
can occur quickly, especially cyanide poisoning

44. Drowning The diagnosis of drowning - exclusion Diagnosis Diatoms
The autopsy is usually negative
Diagnosis
Body is wet, or is found in water.
There may be injuries from being in the water
Tears and scrapes skin from impacts against boats or bridges
Feeding by marine life - skin of the face, especially around the mouth, nose, and ears
Abrasions may be found on the forehead, knees, and backs of hands from scraping
No external signs of trauma
Froth in the nose and mouth
Wrinkling of the skin on the hands and feet
Injuries to the body may occur from CPR attempts or from removing the body from the water.
Heavy, wet lungs in those individuals who drown in salt water,