CCTV and facial mapping Flashcards
in relation to automated face recognition in public places, what percentage of innocent citizens have been identified as wanted criminals by metropolitan police and South Wales police?
- metro - over 98%
- South Wales - 91%
how many CCTV cameras are there in the UK?
4.2 million.
name ways CCTV cameras can reduce crime.
- risk of being caught or punished deters offenders
- encourages natural surveillance
- public more security conscious
- facilitates security and police to locations where suspicious behaviour is occurring.
- show crime is taken seriously, so deter offenders.
a study shows that CCTV in the uk only reduces crime by …%
16%.
name another way to reduce crime, that corresponds with CCTV.
- improved street lighting.
give evidence from M+Bs (2008) study that unfamiliar face encoding is poor.
error rates in unfamiliar matching tasks (delay, simultaneous, no distractors).
what percentage of correct matches did jurors identify between “live” person and person on high quality video?
50% match, reminder mismatch.
name factors that worsen matching ability.
- target is wearing disguise
- delay between filming and test
in D+Vs study, did participants make more false negative decisions, or more false positive decisions?
false negative (22%): false postive (17%). - saying person is different when the same.
define the aim facial mapping.
to determine whether two images show the same person or different people.
name the various techniques of facial mapping.
- measurements from images
- chimeric faces
- video wipe techniques
- photo-anthropometry
true or false: anthropometry is a reliable technique.
false, all measurements are equally poor.
what is the name of the scale used to express opinion on potential matches in court?
the broomy scale.
give two examples of a technique used by facial mappers that can be viewed as bias.
- aligned chimeras can evoke holistic processing and a bias towards “same” responses.
- facial video ‘wipes’ can evoke a bias toward “same” responses.
