The collection and processing of Forensic Evidence

Question 1

What is one motivating factor and bias when experts are collecting evidence?

Answer 1

Finger print experts are emotionally driven and motivated which can an impact on the final results.

Question 2

Who researched into motivations of workers?

Answer 2

Charlton

Question 3

What sample did Charlton use?

Answer 3

Interviewed 13 fingerprint experts from a variety of law enforcement agencies

Question 4

What did Charlton find?

Answer 4

Their main motivations were job satisfaction, satisfaction of catching the criminal and solving cases and solving high profile cases.

Question 5

What is another example of finger print experts being motivated by emotions?

Answer 5

The Brandon Mayfield Case.

Question 6

A brief summary of what happened during the Brandon Mayfield Case.

Answer 6

There was a train bombing in Madrid which killed 191 people and injured 1800. A fingerprint left n the bag was matched to Brandon who was a recently Muslim convert. All experts agreed the fingerprint was his, until Spanish police found that it wasn’t.

Question 7

What are the three categories of cognitive bias?

Answer 7

Expectation bias, Confirmation bias and contextual bias.

Question 8

What is expectation bias?

Answer 8

Where the expectations of what have happened affects what is actually happened.

Question 9

What is confirmation bias?

Answer 9

People test hypotheses by looking for confirming evidence rather than for potentially conflicting evidence.

Question 10

What is contextual bias?

Answer 10

When someone has other info aside from that being considered which influences the outcome of that decision. E.g finding out they are finding evidence for a murder apose to a bike being stolen.

Question 11

Who researched into the effects of contextual biases?

Answer 11

Dror.

Question 12

What sample did Dror use?

Answer 12

27 university volunteers with a mean age of 23.

Question 13

What were the ppts in Dror sample manipulated by?

Answer 13

Providing background info including disturbing images.

Question 14

What was the sample of 27 split by?

Answer 14

Either having a clear fingerprint or having a more ambiguous and less clear (more representative of real life).

Question 15

What two types of emotional states were used?

Answer 15

Either a high emotional context like murder or a serious attack, or a low emotional context crime like a theft of a bike.

Question 16

What was the DV in Dror’s study?

Answer 16

They were measured on how many matches were made.

Question 17

What is a piece of quantitative data which can be found in Dror’s study?

Answer 17

In the unambiguous condition matches were unaffected by context. As, in the ambiguous condition, 58% were matched in the high emotional context condition, compared to 49% in the low condition.

Question 18

Who was the key researcher for this section?

Answer 18

Hall and Player.

Question 19

What did Hall and Player aim to investigate?

Answer 19

H+P aimed to test if context affected fingerprint identification by fingerprint experts.

Question 20

What are two controls that made the experiment as naturalistic as possible?

Answer 20

They were asked to participate at their normal working hours and could stay or go as they pleased.

Question 21

What was the IV in H+P research?

Answer 21

Whether the ppts was in a high context or a low context scenario.

Question 22

What were the 3 DV’s in H+P research?

Answer 22

Whether the ppt had read the crime report or not, whether the ppts matched the fingerprint and whether they were confident or not to prevent the evidence in court.

Question 23

What sample was used in H+P research?

Answer 23

70 fingerprint experts who worked for the Metropolitan police with the mean length of experience at 11 years.

Question 24

What was the fingerprint in H+P research printed onto?

Answer 24

A £50 bank note

Question 25

How many were in the low context group and what was on their examination report?

Answer 25

35 ppts with a scenario relating to forgery.

Question 26

How many were in the high context group and what was on their examination report?

Answer 26

35 ppts with a scenario of a murder.

Question 27

What were ppts in H+P research then asked to do?

Answer 27

Asked to compare the fingerprint with another 10 fingerprints with an examiners report.

Question 28

After completing the experiment, what question were they asked on the feedback sheet?

Answer 28

Asked if they felt their judgement had been affected by the examination report.

Question 29

What statistics were found about the crime report?

Answer 29

57/70 had read the crime report with 30 in the high context group and 27 in the low context group.

Question 30

For those who had read the high context, how many felt affected compared to the low context?

Answer 30

52% said they felt affected compared to 6% in the low context scenario.

Question 31

What was not found in the results with a stat to back it up?

Answer 31

The context dd not effect the professionals decision making as 6 in the high group saw the fingerprint as identification and only 7 in the low context group.

Question 32

What is the first technique which reduces expectation bias?

Answer 32

The latent mark should be analysed independently before analysing the comparison print.

Question 33

A piece of research to to back up comparing the latent mark independently?

Answer 33

Dror.

Question 34

What did Dror find?

Answer 34

Found that fingerprint examiners differed in reliability. As they found that if the comparison was viewed first, fewer key prints of the latent print.

Question 35

What was another application made to do with reducing context effects?

Answer 35

The fingerprint expert should be blind to any crime evidence.

Question 36

Who researched into combating contextual bias?

Answer 36

Dror.

Question 37

What did Dror find about context and crime?

Answer 37

The more matches were made with more emotional crime details.