crime- collection + processing of forensic evidence (bio)

Question 1

what does latent mean?

Answer 1

something that is left behind at a crime scene

Question 2

give two background studies for C+P of forensic evidence

Answer 2

• Brandon Mayfield: bombing in spain
  
  • shows fingerprint analysis is not very objective and not full proof
• Charlton: motivating factors
  
  • asked fingerprint analysts what drives them
  • rewards, hope+ satisfaction, case importance, feelings associated
• Dror: high emotion context
  
  • unambiguous fingerprints given to uni students
  • either high or low emotion context
  • more likely to make a match with high emotional context

Question 3

What are did Dror believe affected finger print analysis

Answer 3

cognitive biases
- reasons for human error

Question 4

what is confirmation bias?

Answer 4

intentionally look for evidence that would validate their current beliefs
- in more evidence that contradicts their beliefs.

Question 5

what is an observer or expectancy bias?

Answer 5

• expert anticipates the outcome as a result of information from and initial observer and the outcome

Question 6

what is selective attention?

Answer 6

prior expectation can lead to the ‘filtering out’ of ambiguous elements in a partial or ambiguous print where a ‘close call’ has to be made to create a match

Question 7

what is conformity affect?

Answer 7

if asked to validate work of the previous person then may unconsciously agree

Question 8

what is need determinism

Answer 8

desire to solve quickly

Question 9

What is forensic evidence?

Answer 9

biological evidence that can be used in court e.g hair , DNA, sperm, saliva

Question 10

what is top down processing?

Answer 10

• have an idea of who the suspect could be
• have evidence about a crime first and then you investigate. Starts with the big picture and then fills in the details.

Question 11

What is bottom up processing?

Answer 11

• look at evidence first and then build a picture
• no suspects

Question 12

What is the previous research for Hall and Player?

Answer 12

• fingers can be poor quality and therefore judgment is subjective
• dror found emotional context can affect decision making but only looks at non experts

Question 13

what is the aim for Hall and Player?

Answer 13

To see if trained fingerprint experts are affected by the emotional context of a case

Question 14

What is the research method for Hall and Player?

Answer 14

• Lab experiment but as naturalistic as possible
• IV : high ( murder) or low ( forgery) emotional context
• DV : whether read report and whether fingerprint was match, not a match, insufficient detail
• independent measures design

Question 15

What was the sample for Hall and Player?

Answer 15

• Volunteers
• 70 experts
• MET police
• experience between 3 months - 30 years

Question 16

What was the procedure for Hall and Player?

Answer 16

• particpants randomly allocated group
• fingerprint on 50£ that was obscured and of poor quality
  -all 14 copies of the mark were compared for consistency
• then given to ppts and asked for their opinion if there was a match
• eone group told it was forgery the other it was murder
• Ps given envelope with one of the test marks, a 10-print fingerprint form, and a sheet of paper telling them that the print was of the right forefinger
• Ps asked if print was a match, not a match or if there was insufficient detail to decide. They were also asked to elaborate on their findings by providing observations and opinions.
• Ps were asked if they had referred to the crime scene report and if it had affected their analysis.

Question 17

what were the results for Hall and Player?

Answer 17

57/70 said they read report
( 30 from high context)
- 52% from 30 pts in high emotional context said they were affected
- but 6% for low
- similar results at the end

Question 18

what were the conclusions for Hall and Player?

Answer 18

emotional context does not affect experts
- further research is needed

Question 19

What the applications for c+p of forensic evidence?

Answer 19

• educating judgies, juries and detectives about S+W of froensic science and its subjective nature
• use bottom up rather than top down as its more objective
• blind testing to avoid conformity bias
• falsification method: find evidence on why they don’t match rather than why they match
• Six Pack idea: give them multiple fingerprints so that they can compare all fingerprints and find most similar ones
• cognitive training: training forensic examiners to acknowledge and minimise bias