SHOT THROUGH THE HEART, PART II: Gunshot Residue

Now let's look at the other end of the gun, for gunshot residue can also refer to what winds up on the victim. When a gun is fired, not just the bullet comes out of the end of the muzzle. Tiny particles of gunpowder with spew out in an ever-widening circle until they lose momentum and fall to the ground. There will also be a cloud of gray matter (fouling), composed of tiny metal particles, mostly lead, scraped from the sides of the muzzle and the sides of the bullet as they encounter each other. This cloud will only travel up to six inches, so if there is a circle of black soot around the bullet hole in the victim's shirt, you know the killer got up close and personal. If the killer got very close, then the bullet hole may appear to be more of a rip than a hole, a cross-shaped pattern of jagged tears. This is known as a 'contact' wound-the muzzle of the gun was pressed against the person and the expanding gases from the muzzle caused the shirt (and, usually, the wound) to more or less explode. A neater hole with no fouling implies that the muzzle was more than 6 inches away.

Flecks of gunpowder may be visible with a stereomicroscope. Gunpowder comes in ball, rod and flake (or disc) shapes, but the most common is flakes, which look like flat discs. They might have holes in them, which increases the surface area for faster burning.

Burnt or partially burnt particles of gunpowder can be found on the clothing with a Griess test (also known as a modified Walker test). This is an absurdly simple test which can tell you terribly important things. A piece of treated photographic paper is placed face up, the article of clothing is placed face down, and a piece of gauze soaked in acetic acid is placed on the inside of the clothing. This is heated with an iron and voila, the nitrites in the gunpowder produces orange dots on the photographic paper. Since the gunpowder spreads out as it moves through the air, the amount and grouping of orange dots tells you something about where the muzzle of the gun was. (Not where the shooter was, just the gun. He might have it close to his body, or fully extended. He might have really long

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