2. Hall and Player (2008) Flashcards
Hall & Player (2008) Key Question
Will The Introduction Of An Emotional Context Affect Fingerprint Analysis and Decision-Making?
Background
Dror et al. (2005) gave university research students either good quality or incomplete, poor quality fingerprints to study and a low level or high level emotional stimuli.
The results showed that students were affected by the emotional context and this interfered with their decisions, making them more likely to make misidentifications when analysing poor quality or ambiguous fingerprints.
Aim
To investigate whether trained fingerprint experts make misidentifications due to emotional bias.
Method and variables
Lab experiment to test the effect of context on fingerprint identification by fingerprint experts.
Independent measures design – low or high context group (IV)
DV = 1. whether p’s read the report before the analysis, 2. whether they could make an identification, 3. whether they would present it in court
Sample
70 fingerprint experts volunteers from the Metropolitan Police. Self-select sample
Randomly allocated to low or high context condition
Between 3 months & 30 years experience.
Procedure
Participants were given.
- Fingermark
- 10 prints from suspect
- Crime report
Each participant carried out the analysis in a fingerprint analysis room at Scotland Yard and was allowed access to a fingerprint magnifying glass and an optical magnifying unit.
Procedure pt2
They were asked to treat the experiment as they would a typical day and no time limit was put in place.
The low-context group were given a crime scene report referring to an allegation of forgery. It stated that a ‘‘Suspect entered premises and tried to pay for goods with a forged £50 note. The forgery was spotted by cashier. Suspect then decamped (left)’’.
The 35 participants in the high-context group were given a report about an allegation of murder. The final wording on the report read ‘‘Suspect then fired two shots at victim before decamping’’.
Procedure pt3
The experts were then asked to consider:
1. Whether the mark was either an identification/match,
2. Not an identification/match, insufficient (not enough detail to undertake a comparison),
3. Insufficient detail to establish identity (some agreement).
They also completed a feedback sheet which asked whether they had referred to the crime scene examination report and if so what information they had read and whether they felt that the information contained on the report had affected their analysis and if so, how.
Results
Overall, 81.4% indicated that they had read the crime scene report before examining the prints.
52% of those who had read the high-context scenario felt that they were affected by the information given on the examination report, compared to only 6% in the low-context scenario.
The final decisions made by the experts were very similar regardless of the emotional context and were not statistically significant.
17% of those given the high context and 20% of those given the low-context scenario were confident enough to present the mark as a positive identification to the court; this was not a significant difference.
Conclusions
- Although emotional context affects a fingerprint expert’s analysis it does not have any effect on their final decisions.
- The severity of a case also affects analysis, but again does not affect the expert’s final decisions.
- Fingerprint experts are adept at dealing with fingerprint analysis in a non-emotional, detached manner.
- But there may be motivating factors and bias in the collection and processing of forensic evidence.
Why are these results useful?
The study showed that within the research fingerprint experts final decision about a match was not influenced by the severity of the case.
The feedback sheet did suggest that information from the crime scene report did influence they way they thought about the case. Therefore there was an element of contextual bias.
Evaluation sheet example
Evaluation - Usefulness of the research; (practical applications)
In the real world contextual bias could bias a fingerprints experts judgement, therefore in order to ensure the reliability of forensic evidence, fingerprint experts should not be shown the crime scene report.
This ensures that their judgment is made using bottom up processing, judgment is made using the finger mark and not bias by other contextual information.
a) Explain how the research by Hall and Player (2008) could be used to improve fingerprint identification. [10]
5 ao1 = Aim
Sample
Procedure
5 ao2 = Apply the findings to the question – give an overview of the results
Conclusions – what does this mean?
How can this be used to improve fingerprint identification?
AO1 = 5 = Aim, sample, procedure
Possible emotional bias which could affect the process of identifying fingerprints
70 experienced forensics 3 months – 30 years
£50 note ambiguous finger-print
High context – fired 2 gun shots at the victim
Low context – forgery
Anytime during the day come in and process the prints
Researcher was there to answer any questions
Completed a feedback sheet
AO2= 5
Would you take them to court – the context didn’t affect the chances of them being taken to court – 17% (high) and 20% (low)
Did you read the report and did it affect your analysis? 81% had read it and 52% of the high condition said it had affected their analysis, compared to 6% from the low condition.
Improvements – blind testing – de-biasing
a) Explain how the research by Hall and Player (2008) could be used to improve fingerprint identification. [10] examplar
The research by Hall and Player highlights possible emotional bias which could affect the process of identifying fingerprints. In the study they created an experiment where 70 experienced forensic scientists were asked to compare a smudged fingerprint on a £50 note with a reference set of prints. This is a very subjective decision and could possibly be influenced by many cognitive factors.
The independent variable was the information that was included in a crime report supplied with the prints. Half were given a crime report describing fraud involving passing forged notes where the suspect fled the premises after the shop assistant spotted that the money was fake, this was the low emotional context condition. The other half were given the same information but at the end of the description it stated that the criminal fired two shots and killed the victim and then fled, this is the high emotional context condition. The reason for this was to see whether an emotional context influences the accuracy of the scientists.
AO2 = When comparing the conditions there was little difference in identification rates between the high emotional context condition and low emotional context condition.
This suggests that the emotional context actually had little effect on the sample in terms of their identification of the fingerprint.
However, the participants were asked at the end of the study if they had read the crime report which contained the details of the crime, and if they had, did they think it had affected their analysis. 50% of the high condition said it had affected their analysis, compared to 6% from the low condition.
This result does suggest that emotional context can affect the fingerprint experts thinking, but maybe not to the extent of biasing their judgements in this artificial scenario. In the real world, emotional context may be more influential.
To improve the future identification of fingerprints forensic experts should be “blind” to the details of the crime, being provided only with the fingerprints and no crime report.
This would ensure that all finger print identifications would be carried out in exactly the same way with no bias affecting more or less violent crimes. Forensic scientists could be more objective in their analysis if they are unaware of the contextual details of a crime. This is known as de-biasing
