Test 2 Flashcards
Defect
Imperfection; deficiency
Abrasion collar
Circular perforation and blackening effect of the skin as the bullet passes through the skin
Fouling, smudging, or smoke
Burned gunpowder is deposited on skin and produces an area of soot deposited around the wound.
-dirty/grimy appearance easily wiped off skin, indicates gun held close to victim but no contact
Stippling
Powder tattooing
- pinpoint hemorrhages due to discharge of burning powder against skin
- CANT be wiped away
Stellate
Cross-shaped or star shaped
Searing
Singeing effect due to discharge of flame from muzzle
-yellow or black discoloration around wound edges
Reentry
If bullet has already passed through another body part then re-enters, an irregular wound will result which will look like an exit wound.
Ricochet wound
If bullet has struck something else before body, wound will be irregular
Intermediary target
Any object between muzzle of firearm and skin
Punctate abrasions
Marked with dots; pinpoint punctures on surface.
7 factors that affect characteristics of the wound and change its appearance.
- Distance
- Ricocheting
- Type of ammunition
- Passage through body
- Passage through clothing
- Type of weapon
- Part of body affected
Bullet firing sequence
- Fire/flame emitted from barrel (not far)
- Smoke follows flame (a little further)
- Bullet emerges from barrel (goes greatest distance)
- Additional smoke and grains of burned and Unburned gunpowder follow bullet out of barrel
Range of fire
Muzzle to target distance
How are bullet wounds classified by range of fire?
Contact, intermediate, distant
Contact range of fire
- muzzle held tight to skin
- gunpowder residue on edges or in wound
- may be burning or reddening in surrounding skin
- skin tearing(over bone/high gas)
- soot on skin notes that there was a little distance between
- 6-8 inches
- contact wound:cross/star shaped handgun wound
- muzzle imprint mirrors contours of muzzle
When are intraoral gunshot wounds best analyzed?
After tongue is cut out
Intermediate range of fire
- punctate abrasions from gunpowder striking and abrasions skin
- stippling can’t be washed
- gunpowder in skin and in abrasion can be washed
- radius of stippling determines range of fire
- 8 inch to 3.5 feet
- soot and stippling more concentrated around wound and decrease as they move away
- increase range of fire; increase area of stippling; decrease density of stippling.
Distant range of fire
- greater than 3.5 feet
- No fouling or stippling
- round/oval wounds depending on angle
- may have surrounding bullet holes
Entrance wound
- smaller than exit
- round neat hole with abrasion coat and grey/black edges
- less blood
Exit wound
- Larger than entrance
- ragged edges looking like stellate
- irregular
- more blood
Bullet and body
- bullet strikes skin causing indentation
- bullet perforates skin and bored through causing circular perforation
- Blackening and grime on wounds edge by skin wiping off bullet residue as it e gets tissue.
- skin returns to former position making wound look smaller
Shotgun wounds
- cartridge powder explodes
- 5 components released thru barrel
- hot gases
- smoke
- flame
- pellets
- wads
Shotgun firing
- charge and all birdshot pellets leave barrel I’m a group
- orange flame makes searing in close range wounds
- soot cloud and gunpowder make soot and stippling in close and intermediate wounds
- air resistance pulls shot Sleve back, petals open, and spread out the longer they fly
Most common sharp force injury weapon?
Knife
Cutting wounds
- parallel
- incision made by sharp instrument longer on skin surface than deep
- edges of wound are sharp and usually not ragged or abraded
- edges of wound remain together if parallel cut, gaping if not
Characteristics of cutting wounds
- Clean/sharp edges
- Minimum bruising
- Longer than deep
- Bleeds freely
- hard to know weapon in cuttings
Stabbing wounds
- perpendicular
- extend through tissues and bone into organs
- sharp pointed instruments
- wounds vary based on attack (twist, pulled out, etc)
- entrance wound can mislead because of skin elasticity
Characteristics of stabbing wounds
- Deeper than wide
- Possible damage to vital organs beneath skin and none
- Internal bleeding w/little or no external blood
Factors which can determine a stab wound
- Type of weapon
- Direction of injury
- Position of the victims
- Clothing worn can also correlate to bodily injuries with years or rips to clothing
Perforating
Going whole way through
Penetrating
Part way through
Documenting stab wounds
- Location of body
- Measurements from landmark like top of head and distance from midline of body
- Size and shape of wound
- Orientation
- Associated abrasions and exchymosis
- Tissues injured (wound track)
- Direction through the body (wound path)
- Length of wound track through tissues beginning from skin
- Presence of tool marks on cartilage and bone
Chop wounds
- intermediary b/n blunt and sharp force that involve both tissue laceration and slicing
- most common objects are axes, machetes, propeller/machine blades
Overkill
Body sustaining tens or hundreds of stabs and cut wounds from a highly emotional setting involving sex or drugs
Homicide stab wounds vs suicide
Homicide
- location and type
- multiple cut or stab wounds to neck, face, and extremities
Suicide
- multiple incised wounds of varying depths on neck or wrist
- superficially incised wounds adjacent to a major incised wound (hesitation marks)
Severity, extent, and appearance of Blunt trauma injuries depend on :
- Force to body
- Time over which force is delivered
- Region struck
- Extent of body surface over which force is delivered
- Nature of weapon