A 32-year-old man is brought to the emergency department with a stab wound to the left anterior chest. On examination, the wound is 2 cm long with clean, sharp margins and minimal surrounding tissue damage. Regarding the forensic characteristics of stab wounds, all of the following are TRUE EXCEPT:

Explanation

## Forensic Characteristics of Stab Wounds **Key Point:** Stab wounds are penetrating injuries caused by pointed or sharp instruments. The critical distinction is that stab wounds typically show **minimal tissue bridging** and **clean margins** (similar to incised wounds), NOT marginal abrasion and tissue bridging (which are features of lacerations). ### Comparison: Stab Wounds vs. Incised Wounds vs. Lacerations | Feature | Stab Wound | Incised Wound | Laceration | |---------|-----------|---------------|------------| | Margins | Clean, sharp | Clean, sharp | Irregular, bruised | | Tissue bridging | Minimal or absent | Minimal or absent | Present (vessels, nerves visible) | | Cause | Pointed/sharp instrument | Sharp instrument (slash) | Blunt force trauma | | Depth | Often deep relative to length | Variable | Usually wider than deep | | Marginal abrasion | Absent or minimal | May be present | Typically present | **High-Yield:** Stab wounds do NOT characteristically show marginal abrasion and tissue bridging. These features are typical of lacerations (blunt force injuries). Stab wounds have clean margins like incised wounds because they are caused by sharp instruments. ### Forensic Reconstruction of Stab Wounds **Clinical Pearl:** The wound tract within the body is typically longer than the skin wound because: - Skin elasticity causes the skin to retract after the instrument passes through - The instrument may penetrate deeper tissues than the skin surface measurement suggests - Examining the internal wound tract helps determine the actual depth and direction of the injury ### Instrument-Specific Features **Key Point:** Different types of pointed instruments produce characteristic injuries: - **Pointed instruments** (e.g., thin knife): Clean, narrow wound tracts with minimal surrounding tissue damage - **Blunt-pointed instruments** (e.g., screwdriver): Wider wound tracts with more surrounding tissue trauma - **Serrated instruments** (e.g., saw-tooth blade): Irregular wound margins with tissue bridging **Mnemonic: STAB WOUND FEATURES — S**harp margins, **T**ract deeper than skin, **A**bsent bridging (usually), **B**lunt-pointed variants exist [cite:Reddy Forensic Medicine 33e Ch 8]