the collection and processing of forensic evidence

Question 1

how are fingerprints used?

Answer 1

have three specific classes from their visual appearance

Question 2

what types of fingerprints are there?

Answer 2

arches, loops and whorls

Question 3

what does 5% of the population have?

Answer 3

arches

Question 4

what does 60% of the population have?

Answer 4

loops

Question 5

what does 35% of the population have?

Answer 5

whorls

Question 6

why do errors occur?

Answer 6

although it appears objective, it is still a human expert who makes the final decision on whether forensic evidence is a match or not

Question 7

what can there be errors with?

Answer 7

fingerprints, blood evidence, hair comparisons and bite marks

Question 8

how can these errors be explained?

Answer 8

cognitive bias and confirmation bias

Question 9

what did dror (2011) find?

Answer 9

that different fingerprint examiners differ from one another and themselves over time

Question 10

what did dror (2011) find about emotional context?

Answer 10

by adding the context of the crime/pressure, decision making can be easily affected by our emotional context. in a high emotional-context there is an increased likelihood of a match being made with an ambiguous print.

Question 11

what was hall and player’s (2008) aim?

Answer 11

to see if emotional context would bias the judgement of expert analysts

Question 12

what were hall and player’s (2008) participants?

Answer 12

70 qualified fingerprint experts working in london met police, and had average experience of 11 years.

Question 13

what was hall and player’s (2008) design?

Answer 13

superimposed a fingerprint onto a £50 note on a card- which they ensured was ambiguous and poor quality from other experts’ confirmation. given a typical case report and told to treat it like a normal day- they were able to talk, but not about the task at hand.

Question 14

what was hall and player’s (2008) IV?

Answer 14

low or high emotional context- randomly assigned to groups of 8

Question 15

what was the low emotion condition?

Answer 15

crime was a forgery

Question 16

what was the high emotion condition?

Answer 16

same report except for the last sentence, where the crime became a murder

Question 17

what was hall and player’s (2008) DV?

Answer 17

whether the analysts reported feeling affected by the scenarios, and whether this affected their final decision about the fingermark

Question 18

what were hall and player’s (2008) results?

Answer 18

only 57/70 participants read the crime scene report, 52% in the high-emotion context felt affected by it, and 6% in the low-emotion
however no significant differences were found in their decisions as they were professionals

Question 19

what did hall and player’s (2008) conclude?

Answer 19

emotional context does affect experts’ feelings, but it does not influence the final outcome of their analysis. compared to dror’s study, this shows that fingerprint experts are better at doing analyses in a detatched manner than non-experts.

Question 20

what was the issue with dror’s study?

Answer 20

used students, who were not experts

Question 21

examples of debasing techniques in the collection of evidence

Answer 21

blinding precautions; independent checking

Question 22

what are blinding precautions?

Answer 22

giving the forensic examiner only the necessary information to conduct an effective examination, which guards against contextual bias

Question 23

what is independent checking?

Answer 23

the independent application of analysis, comparison and evaluation by another examiner who does not know the conclusions of the first examiner, which minimises the effect of confirmation/cognitive bias