impression evidence Flashcards
Types of impressions
latent impression
plastic impression
patent impression
examples of impression evidences are?
bite marks - marks on a fired bullet
footprints - tire tracks
fingerprints - tool marks
what is a patent impression ?
Two-Dimensional (2-D) impressions that are already visible
what is a latent impression ?
Hidden Impression requiring special techniques to be visible
what is a plastic impression ?
Three-Dimensional (3-D) impressions cast in soft materials, such as soil and snow or blood.
what are the collection methods for 2-D impressions?
- photography can be used
- They may also be collected using an electrostatic dust lifting process.
what are the collection methods for 3-D impressions ?
- photography
- casting
TRUE or FALSE : forensic investigators have to memorize tire brands and models in order to tell tire tracks apart.
FALSE
-Tire databases are available help investigators determine the brand and model of the tire that left the impression
what features should you analyze for tire-track evidence ?
- tread pattern
- Width & depth of the tread pattern
- individual characteristics or defects due to wear patterns
what is a tread pattern ?
the unique design of a tire’s surface.
The distance from the center of the tread pattern on the left tire to the center of the tread pattern on the corresponding right tire is…
Track Width
The distance from the center of the front axle on a vehicle to the center of the rear axle.
Wheel Base
A measure of how tight a circle can be driven by a vehicle
Turning Diameter
Tool marks can be classified two ways:
impression
scratches
