1. Chapter 14 Firearms, Tool Marks, and Other Impressions

2. Other Impressions What does “other” include? Main concern The process
Shoe, tire, or fabric impression
Preservation of the impression or its reproduction for later examination in the crime lab
1st – must be photographed
Include a scale
Show all observable details
Side lighting for illumination helps highlight ridge details
Show position of impression relevant to crime scene

3. Other Impressions How to get the original impression
If it’s on glass, paper, or floor tile; easily removed
Similar to lifting a fingerprint
Place lifting material over impression, use roller to eliminate air pockets, lift
Electrostatic lifting device (Pathfinder)
Film placed on top of dust print mark, pressed down, high-voltage electrode used to create static charge
Dust sticks to mylar sheet

4. Other Impressions Lifting Impression in soft earth
Use a Class 1 dental stone – gypsum or plaster of paris
Make the paste and gently pour into impression
Snow Impression Wax to use on impressions left in snow that would be destroyed w/ other methods

5. Other Impressions
Test impression necessary to compare the charac of suspect item w/ evidence impression
Value of impression as evidence depends on # of class & individual characteristics found
Class characteristics – size, shape, design of tread
INDIVIDUAL characteristics – wear, cuts, gouges, or other damage
Need sufficient # of pts of comparison
What do you compare?
aol.com/varfee/ mastssite

6. Famous “other” impression
Bite marks!
Make a mold of suspects teeth/bit impression to compare to photo of bit marks from victim
Most famous – Ted Bundy – it was main piece of physical evidence that helped convict him
Forensic Odontologist