In a stab wound caused by a double-edged knife, what is the characteristic appearance of the wound margins?

Explanation

## Stab Wound Characteristics with Double-Edged Weapons **Key Point:** A **double-edged knife** produces a stab wound with **both margins clean and sharp**, reflecting the symmetrical cutting edges of the weapon. ### Wound Margin Patterns by Weapon Type | Weapon Type | Wound Margin Appearance | Characteristics | |-------------|------------------------|------------------| | **Double-edged knife** | Both margins clean and sharp | Symmetrical, equal bevelling on both sides | | **Single-edged knife** | One margin clean (sharp edge), one irregular (blunt edge) | Asymmetrical appearance | | **Pointed instrument (spike/awl)** | Margins may be irregular or clean depending on angle | Minimal tissue damage at margins | | **Blunt instrument** | Both margins irregular, bruised, crushed | Tissue damage beyond wound edges | **High-Yield:** The **margin pattern of a stab wound can help identify the weapon type**—a critical forensic principle. Double-edged weapons create symmetrical clean margins; single-edged weapons create asymmetrical margins with one clean and one irregular edge. **Mnemonic:** **DEBS** — Double-Edged, Both Sharp; Single-Edged, Staggered (one sharp, one bruised). ### Forensic Significance - Double-edged knife wounds show **equal bevelling** on both margins - Single-edged knife wounds show **asymmetrical bevelling**—the sharp edge produces a clean margin, the blunt edge produces an irregular/bruised margin - The **angle of entry** also affects margin appearance; perpendicular entry produces sharper margins than oblique entry - Examination of margin characteristics can help reconstruct the weapon and manner of injury