Sharp Impacts/Cuts pt. 2

What type of injury is produced by a sharp object?

Sharp force injury

What is a sharp object?

An object with a sharp edge or pointed extremity

What is the most common weapon producing sharp force injuries?

Knife

What are the four categories of sharp force injuries?

Incised wounds, stab wounds, chop wounds, and atypical wounds

What feature distinguishes a stab wound from an incised wound?

Depth of the wound track relative to skin wound length

What sharp force wound is longer than it is deep?

Incised wound

What sharp force wound is deeper than it is long?

Stab wound

What type of wound is produced by a heavy object with at least one sharp edge?

Chop wound

What wound pattern is most commonly associated with homicide?

Multiple deep stab wounds

What wound pattern is most commonly associated with suicide?

Progressively deeper wounds ending in one fatal stab wound

Are fatal accidental sharp force deaths common or rare?

Rare

What are incised wounds also called?

Cuts or slashes

What is a common medical example of an incised wound?

Surgical incision

What motion produces an incised wound?

Tangential slicing movement across the skin

How do incised wounds usually compare in length and depth?

Longer than deep

What do the wound edges of an incised wound look like?

Cleanly divided and sharply separated

What critical feature is absent in an incised wound?

Tissue bridges

What feature differentiates an incised wound from a laceration?

Absence of tissue bridges

What causes tissue bridges?

Incomplete tearing of blood vessels, nerves, or connective tissue

What do tissue bridges indicate?

Laceration from blunt force trauma

Where is an incised wound usually deepest?

At the entrance point

Where is an incised wound usually most superficial?

At the exit point

What does a superficial linear scratch caused by a blade represent?

Sharp force abrasion

What occurs when a blade penetrates deeper into tissue?

Cut

What occurs when a blade completely detaches a body part?

Mutilation

What are wound tails?

Linear scratches at the ends of an incised wound caused by blade movement

What does a wound tail help determine?

Direction of blade movement

What does the entrance tail typically look like?

Shorter and deeper

What does the exit tail typically look like?

Longer and more superficial

Why is the entrance tail deeper?

Greater pressure at first contact

Why is the exit tail more superficial?

Blade rises from skin and pressure decreases

Can wound tails be absent?

Yes

Why might an entrance tail be absent?

Pressure was so great that skin separated immediately

Why might an exit tail be absent?

The wound occurred on a convex surface

What are wrinkle wounds?

Multiple cuts created by a single cut across folded skin

What body areas commonly show wrinkle wounds?

Hands, knuckles, and breasts

What major vessels make incised wounds potentially fatal?

Neck and wrist blood vessels

Are incised wounds usually fatal?

No, unless major vessels are involved

What are stab wounds also called?

Puncture wounds

What motion creates a stab wound?

Perpendicular penetration into the body

What is the defining feature of a stab wound?

Penetration

How does a stab wound compare in depth and length?

Deeper than long

What three components make up a stab wound?

Entrance wound, wound track, and sometimes an exit wound

What additional injuries may surround a stab entrance wound?

Bruises, abrasions, handle marks, or guard marks

What is the wound track?

The path traveled by the weapon through the body

Do stab wounds usually have exit wounds?

No

When might a stab wound have an exit wound?

High-energy wounds or extremity wounds

What critical feature is absent in stab wounds?

Tissue bridges

What do tissue bridges suggest instead of a stab wound?

Laceration

What wound shape may occur if a knife is twisted before withdrawal?

V-shaped wound

What wound shape may occur if a knife rotates before withdrawal?

L-shaped wound

What wound shape may occur if a knife twists significantly?

Y-shaped wound

What does an irregular stab wound suggest?

Weapon twisting or movement during withdrawal

What is a handle mark?

Abrasion pattern caused by the knife handle striking skin

What does a handle mark indicate?

The entire blade entered the body

What does a handle mark suggest about force?

Significant force was applied

What type of injury combines sharp and blunt force trauma?

Chop wound

What weapons commonly produce chop wounds?

Axes, machetes, and cleavers

Why is the center of a chop wound clean?

The sharp edge cut through tissue

Why are chop wound margins irregular?

Weight, thickness, and reduced sharpness of the weapon

What injuries commonly surround a chop wound?

Bruising, abrasion, and crushing

Why are chop wounds associated with bruising?

Heavy weapon force causes blunt trauma

Do chop wounds typically have wound tails?

No

Why are wound tails absent in chop wounds?

Pressure mechanism dominates rather than slicing

Can chop wounds fracture bone?

Yes

What skull finding is characteristic of a chop wound?

Linear dent in the skull

What happens if chop wound force exceeds skull elasticity?

Fracture develops

What extremity injury may occur in severe chop wounds?

Partial or complete amputation

What chop wound pattern suggests an axe?

Crushing fragmented wound with fractures

What chop wound pattern suggests a cleaver?

Clean narrow wound without fracture at entry

What chop wound pattern suggests a machete?

Wide irregular wound with bone fragments and fractures

What wound pattern suggests a boat propeller?

Large parallel sliced wounds

Where are boat propeller wounds usually found?

Bodies recovered from water

What finding strongly supports an antemortem propeller wound?

Hemorrhage in surrounding tissue

Does absence of hemorrhage rule out antemortem injury?

No

Why may hemorrhage be absent in water-recovered bodies?

Immersion washes away blood

What injury results from a tangential propeller strike?

Skin or soft tissue flap wound

What wound shape suggests closed scissors?

Triangular wound

What wound shape suggests closed scissors besides triangular?

Rhomboid wound

What wound shape suggests closed scissors besides rhomboid?

Z-shaped wound

What wound pattern suggests open scissors?

Two stab wounds separated by intact skin

What wound shape suggests a Phillips screwdriver?

Cross-shaped wound

What wound shape suggests a flathead screwdriver?

Rectangular wound

What weapon produces a small round puncture resembling a mole?

Ice pick

Why can ice picks penetrate deeply?

Very small pointed tip concentrates force

What wound pattern suggests a kitchen fork?

Four circular punctures

What wound pattern suggests a barbecue fork?

Two or three punctures grouped together

What wound pattern suggests broken glass?

Multiple punctures connected by a circular or semicircular cut

Why must clothing always be examined in sharp force deaths?

To compare clothing defects with body wounds

Why should photographs be taken before manipulating the body?

Medical intervention may alter wound appearance

Why should wounds be numbered?

To accurately document each injury

What can alter wound shape during examination?

Skin elasticity and Langer lines

Why should wound edges be gently apposed?

To determine true wound shape and length

Can wound depth determine exact blade length?

No

Why might a stab wound track be deeper than the blade length?

Body surface compression during stabbing

What should be documented regarding wound direction?

Skin findings and wound track direction

Why must involved organs be documented?

They help determine cause of death

What organs commonly show direct stab injuries?

Heart, lungs, and liver

Why can lung wounds appear longer than the blade?

Lung expansion during breathing

During what breathing phase is the lung easiest to stab?

Inspiration