2. STAB WOUNDS
These are sharp-edge injuries which
penetrate deep inside the body usually into cavities of
the trunk.
Their longest axis is the depth.
Stabs are produced when a sharp-edged pointed
weapon is thrust perpendicular to the body.
4. Description of Stab wounds
Description of stab wound must include
1.Wound of entry
2.Depth and direction
3.Wound of exit
5. Penetrating Wound
• When the weapon enter the body cavity
such as thorax or abdomen injury is
termed as penetrating wound.
6. Perforating Wound
• When the weapon after penetrating the body tissues,
comes out from the other side making an exit wound,
the injury is termed as perforating wound.
7. Descriptors of penetrating wounds
•Site in relation to anatomical
landmarks, midline, heel.
•Shape
•Alignement (horizontal, vertical,
oblique)
•Size : length & width with edges
opposed
•Direction :in 3 planes
8. Descriptors of penetrating wounds
•Depth
•Damage to clothing
•Damage to tissues along track
•Effects : external & internal hemorrhage, pneumothorax,
air embolism
9. WOUND LENGTH
• A straight in and out stab wound is slightly shorter than the width
of the blade due to stretching of the skin over the point of the
knife on insertion and elastic recoil on withdrawal.
• Wound length and width must be assessed with the edges taped
together because the wound is often shortened and widened into
an ellipse by skin elasticity (Langer's lines of tension) and
underlying muscle tone.
10. Wound Length…
• Wound length < blade width
(1) stretching of skin over point on insertion and subsequent recoil on
withdrawal.
(2) tapered blade not fully inserted
Wound length > blade width
• When blade does not pass straight in and out - entry and withdrawal at
angle.
• "Rocking" of knife on withdrawal. Cutting edge extends wound length
• The best indicator of blade width is the shortest (least rocking), deepest
wound (weapon fully inserted)
11. SHAPE OF WOUND
Direction of insertion overhang of upper
edge, bevel of lower edge
• The direction of the wound track
through the tissues is assessed at post
mortem, with the body lying flat on its
back. The position of the internal
organs is different in life, when
standing, sitting and breathing.
12. WOUND TRACK DEPTH
< length of instrument if not fully
inserted
> length of instrument if fully inserted
and body surface compressed e.g.
abdomen, chest.
A small penknife can perforate heart
or abdominal aorta.
13. DEGREE OF FORCE
• Wound depth is a poor indicator of force
applied
• Pressure required to penetrate is often slight
with sharp tipped instrument
• Depends on sharpness of point, not of cutting
edge. Sharp tip requires little force to
penetrate, blunt tip requires greater force.
• quick thrust penetrates skin more easily than
slow, sustained pressure
14. DEGREE OF FORCE….
• Bony damage is useful indicator of depth and implies
significant force.
• Most resistance offered by CLOTHES AND SKIN
• The compressed skin 'gives' suddenly, releasing the
energy stored in the compressed skin and tissue
(elastic reservoir). Once the skin has been
penetrated, the blade slips easily through the
underlying muscle, internal organs and uncalcified
cartilage, without the need for further application of
force.
15. EFFECTS OF STABBING
• Victim may not initially be aware of injury.
• There may be little or no external blood loss.
• Internal blood loss may be profuse and rapidly
fatal or slow enough to allow time for medical
treatment.
• Main effect is bleeding. The time taken to
incapacitate the victim and what actions are
still possible is very difficult to estimate.
16. EFFECTS OF STABBING….
• A stab to the heart may bleed profusely out into the confined
space of the pericardium. If pericardial defect is small or does not
communicate with the pleural cavity cardiac tamponade may
result (200-450ml).
• Left ventricular wound may partially reseal, resulting in slow blood
loss or spontaneous healing. Thin-walled right ventricle less likely.
Great vessels do not re-seal.
17. EFFECTS OF STABBING….
• Rate of bleeding from stab wound to the lung depends on the size
of vessels cut. Large pulmonary veins & arteries branch outwards
from the hilum. Peripheral stab bleeds less and may seal if lung
collapses. Pneumothorax may itself be fatal. Cut through bronchus
may bleed and obstruct airways.
18. EFFECTS OF STABBING….
• Abdominal stab may penetrate major vessels, liver or spleen
with rapid hemorrhage into the
abdominal cavity.
• Stabbing to the head and face may allow penetration of bone in
the region of the eye, nose and temple where bone is relatively
thin.
19. EFFECTS OF STABBING
•Pulmonary air embolism originating in a
partially severed jugular vein may be
rapidly fatal before much blood is lost.
27. STABS, PUNCTURES, PERFORATIONS
Essential points of examination
1. Site and nature of cuts in clothes
2. Site of wounds, height from ground
3. Specifications of wounds
4. Depth and direction of penetration
5. Injuries to organs – cause of death
6. Examination of weapon and co-relation
with injuries
28. Stab Wound Comparison
Suicidal Homicidal Accidental
Numbers Often single Frequently
multiple
Usually single
Tentative
wounds
Mostly
around site of
fatal wound
Rare and
away from
fatal wound
Absent
29. Stab Wound Comparison
Suicidal Homicidal Accidental
Clothing Not
involved
Corresponding
cuts
Involved
haphazardly
Defence
wounds
Absent Often present Absent
Site Accessible Anywhere Anywhere
30. Laceration Incised Stab Wound
01 Production Blunt
Object
Object with
sharp cutting
edge
More or less
pointed objects
02 Site Usually
over bony
prominences
Anywhere Anywhere but
usually chest,
abdomen or
neck
Comparison B/w Lacerated Wound,
Incised Wound and Stab Wound
31. Laceration Incised Stab Wound
03 Shape Usually
irregular
Linear or
spindle shape
Depends on the
weapon
04 Margins Irregular Clean cut and
everted
According to the
nature of
weapon
05 Dimensions Variable Longer than
deep but often
gaping
Depth greater
than length
Comparison B/w Lacerated Wound,
Incised Wound and Stab Wound
32. Laceration Incised Stab Wound
06 Hair and
blood
vessels
Crushed Clean cut Variable
07 Hemorrhage Not
pronounced.
Exception:
scalp
Usually
profuse
Varies – may
be concealed
internally
Comparison B/w Lacerated Wound,
Incised Wound and Stab Wound
33. Laceration Incised Stab Wound
08 Surrounding Abrasion and
bruising
usually
Abrasion and
bruising not
present
Abraded or
bruised due to
thrusting
force or if the
weapon is
blunt
09 Foreign bodies Frequently
present
Normally
free from
foreign
bodies
Foreign bodies
may or may
not be
present.
Comparison B/w Lacerated Wound,
Incised Wound and Stab Wound
