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
advantages of superglue post treatments
easy to use
use on a wide range of non porous surfaces
size of fuming cupboard allows for large items to be analysed
disadvantages of superglue post treatments
requires a specialised chambe to be a fitted with an extraction system
what surfaces can protein stains be used on
mostly on non porous stains
what protein stains are there?
AB1 AV17 AY7
what are the advantages of protein stains
easy to use
cheap
how would you test a coke can for fingermarks?
do a visual examination before anything and take photographs
use a carbon black powder, photograph and then do a tape lift
superglue fuming and BY40
what other evidence could you find in the coke can
DNA
contents such as drug spiking
if blood is on a broken green glass bottle, what tests would you do?
aluminium powder and then a tape lift
superglue fuming and acid black 1
what’s the best enhancement strategy for an envelope
photograph and do a visual examination
separate window from the envelope
for plastic window, superglue fuming and BY40
what evidence could you find on the envelope
DNA
handwriting
trace evidence in he seal e.g. fibres
what are the disadvantages of protein stains
will only stain fingerprints stained with blood or other body fluids
won’t stain fingermarks containing normal constituents of sweat
solvent may damage some surface types
what is ACE-V
analysis
comparison
evaluation
verification
