Stab wound - FMT

• Entry into a body cavity: penetrating wound
• Passage completely through the body with an exit wound: perforating/transfixing wound
  Parikh's Textbook of Medical Jurisprudence, pp. 258-260.

Features of the entry wound

• Usually clean-cut margins with inverted edges.
• Shape may indicate the type of weapon:
  • Single-edged knife: one pointed acute end and one blunt/squared end, sometimes a small tear.
  • Double-edged knife: elliptical or spindle-shaped wound with two acute ends.
  • Round pointed weapon: circular wound.
  • Square pointed weapon: cruciate wound.
• Clothing or foreign material may be driven into the wound.
• Bruising/abrasion around the wound can occur from a blunt blade, forceful thrust, or the weapon's guard/hilt. A guard mark suggests complete insertion of the blade.
• The skin wound does not reliably indicate the exact blade width or length, because of skin elasticity, body movement, twisting, and cutting during withdrawal.

Depth and direction

• Depth depends on blade length, force, angle, and compressibility of the part, so it may exceed the blade length in areas such as the abdomen.
• Direction is assessed from the wound track and, where present, entry and exit wounds.
• One external entry wound can sometimes produce more than one internal track if the weapon is partly withdrawn and reinserted in another direction.
• Do not probe a stab wound in a living person. It can disrupt a clot and provoke severe bleeding.
  Parikh's Textbook of Medical Jurisprudence, pp. 259-260.

Exit wound

• Present only in a perforating injury.
• Often smaller than the entry wound if a tapering weapon was used.
• Edges may be everted.

Medicolegal importance

1. Helps infer the probable weapon type and its cutting edges.
2. Wound track helps reconstruct the relative position of victim and assailant.
3. Guard marks may suggest full blade penetration.
4. Internal organ injury may be severe despite a small, apparently trivial skin wound.
5. Manner may be homicidal, suicidal, accidental, or rarely fabricated. Final opinion requires scene findings, wound distribution, clothing damage, defense injuries, and investigation, not wound shape alone.

Example of documentation