Tool marks can be impressions, cuts, scratches, gouges or abrasions left on an object by a harder instrument. They can be negative impressions made when a tool is pressed into a surface, such as pry marks from a crowbar on a door. Or they can be abrasions from friction, or a combination of both. Examples given include knife marks on bone, fractured knife blades, homemade explosive devices, crimp marks on detonation, cut marks on wire, and pry marks on windows or doors.

1. C H A P T E R X I I
TOOL MARKS

2. A tool mark is defined as any impression, cut,
scratch, gouge, or abrasion, or any other marking
left on an object by another harder object or
instrument. A tool mark may be classified as a
negative impression, as an abrasion or friction-
type mark or as a combination of the two.
Negative impression
is made when a tool is pressed against or into a
receiving surface. This type of mark is usually made
when a crowbar is used to pry open a door or a
window.

4. knife marks on bone
fractured knife blades
homemade explosive devises

5. crimp marks on detonation
cut marks on wire
pry marks on a window or door

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