Unit 10- Impression Flashcards
Patent impressions
- visible
- 2 dimensional
- bloody shoeprints
latent impressions
hidden
- visualized by chemical or physical development
plastic impressions
- 3 dimensional imprints
- usually in snow or soil
electrostatic dust print lifting device
a tool that electrostatically charges particles within dust or light soil which are than attracted and bonded to a lifted film
adhesive gel lifter
allows lifting of dusty shoe print with a sheet of rubber with adhesive layer on one side
casting with dental stone or plaster
used to collect any plastic or 3 dimensional imprint
difference between class and individual characteristics
class: characteristics that are common among a group of footwear/tire
- ex: size, brand/logo, tread design
individual: unique characteristics observed only on an individual footwear/tire
ex: cuts, scratches, debris, wear pattern
information from shoe impressions
- size
- brand.
- weight
- lifestyle
-gender
impression evidence database (3)
- threadmark (footwork impression database).
- solemate: over 30000 footwear reference database
- threadmate: reference collection containing over 8500 vehicle types
conclusions for impression evidence (3)
- k cannot be eliminated as the source of Q impression
- q impression is identified as originating from K source
- K is eliminated as a possible origin of the Q impression
ridge characteristics (minutiae)
- individual characteristics
- the identity, number, and relative location of characteristics that impart individuality to a fingerprint
- 150 minutiae
- most are partial impressions
3 fundamental principles of fingerprints
- fingerprints are individual characteristics
- a fingerprint remains unchanged during an individual’s lifetime
- fingerprints have ridge patterns that permit them to be systematically classified
points of identification
- number of ridge characteristics that are necessary to identify two fingerprints as the same.
- 8-16
international association for identification (IAI)
NO bases exist for requiring a predetermined minimum number of friction ridge characteristics which must be present in two impressions in order to establish positive identification
fingerprint ridges are found on
-fingerprint and thumbs
-palms
-soles of the feet