fingermarks Flashcards
what are the three purposes of fingermark ridges
- for friction (grip)
- to raise up the openings for sweat glands
- to assist in the sense of touch
what are the dips called in between ridges
furrows
what are the three different types of fingermark patterns
- arch
- whorls
- loops
what are the two key features in fingermark patterns
delta
core
on a glass bottle, what two bits pf evidence could there be
- DNA/saliva found the opening
2. contents such as drug spiking
how would you test a glass bottles for fingerprints
aluminium powder and tape lift
superglue fuming and BY40 staining
what is the zephyr brush used for
aluminium powder
what makes a positive print
seeing the ridge details
what makes a negative print
e.g. dust, when the finger lifts off the surface it removes some of the material with it
what’s a impression fingermark
on putty or blue tac,
Explain how a crime scene mark is compared to a suspect fingerprint to determine if they are a match
they use IDENT1 to access all of the biometric prints in the country
the examiner will be looking for similar patterns and ridge detailing, as well as poroscopy, i.e.
what are some porous surfaces
paper
cardboard
wood
plasterboard
what are some non porous surfaces
glass plastic carrier bag drinks can bin liners metal surfaces
advantages of DFO
can develop old marks
easy to use
disadvantages of DFO
won’t develop fingermarks exposed to water