1. Tool Marks

2. Tool Mark
Definition: impression left by the contact of a tool onto a surface
Importance: establish a link between a tool mark and the tool that created it

3. Two Kinds of Characteristics
Class: type of impression, its general shape and its general dimensions
Help determine type of tool and how the mark was created
CANNOT be used for identification of exact tool
Individual: AKA accidental are the striations and small particularities exhibited by the tool that are individual or unique to one tool
These characteristics provide formal identification

4. Two Types
Slipped/Scratches: occurs as the tool drags or slides across a surface, result is series of striations
Ex: keying someone's car, cutting of knife
Molded/Impressions: contact of a tool onto a surface with no lateral motion (no drag or slip) which cause a 3D mold of the tool that contacted the surface
Ex: breaking a door with a pry bar, serial number stamped on a gun barrel

5. Pictures
Slipped
Molded

6. Examination Process
Step 1: Observation, measurement, and description of tool mark
Step 2: Photo’s are taken
Step 3: If the tool cannot be taken as is a cast is made
Step 4: Comparison tool marks are made on a soft surface to not remove or change individual characteristics
Step 5: Compare incriminating tool mark verses comparison mark under microscope

7. Evidence Examples Bolt cutters Screwdrivers and chisels Scissors
Knives and box cutters
Pliers and wrenches
Crowbar
Saws

8. Places to Look for Tool Marks
Wire, chains
Door and window frames
Sections of sheet metal
Safety-deposit boxes, safes
Padlocks, doorknobs
Bolts and locks