Bullet Wipe (Metal Wipe)
Definition
The grey-black ring of bullet-jacket material (grease, metal oxides, carbon) deposited around the margin of an entry hole as the bullet's periphery contacts the wound-channel edges. Asymmetric for oblique entry, symmetric for perpendicular entry.
- Composition
- Grease, metal oxides, carbon
- Location
- Margin of the entry hole
- Symmetric pattern
- Perpendicular entry
- Asymmetric pattern
- Oblique entry
- Field
- Bullet trajectory, entry angle analysis
Common questions
How does the shape of the metal wipe ring help estimate the angle of entry?+
A perpendicular strike deposits a fairly even, symmetric ring around the hole, while an oblique strike concentrates more wipe material on the side the bullet approached from, giving an asymmetric crescent pattern.
Is metal wipe the same thing as a muzzle stamp or soot deposit?+
No, metal wipe comes from contact between the bullet's surface and the wound margin at any range, while soot and muzzle stamps result from discharge gases and muzzle contact only at close or contact range.
Related terms
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- Bullet Trajectory Kit (BTK)
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- Burke and Rowe 1992
- The primary peer-reviewed study of bullet ricochet behaviour on concrete, asphalt, and vehicle metal surfaces, published in the Journal of the Forensic...
- Faro Focus 3D
- A terrestrial laser scanner used for crime-scene documentation, capturing a full-resolution point-cloud model of the scene at millimetre accuracy. Trajectory rods or...
- Keyhole Wound
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- Ortho-Tron Projection Rod
- A commercial trajectory rod system manufactured by Sirchie, widely used by the FBI Evidence Response Team and forensic laboratories internationally, providing standardised...
- Ricochet
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- Single-Bullet Trajectory Analysis (JFK/HSCA)
- The 1979 House Select Committee on Assassinations photogrammetric reconstruction of the Kennedy assassination trajectories, the most extensively reviewed shooting reconstruction in forensic...
- Trajectory Rod
- A rigid fibreglass or aluminium rod inserted through a bullet wound channel and aligned with the channel geometry to define the bullet's...