Criminal: Topic Two Flashcards
What is topic 2?
The collection and processing of forensic evidence
What is the key research for topic 2?
Hall and Player: Will the introduction of an emotional context affect fingerprint analysis and decision making
What did H and P’s sample consist of?
70 volunteer fingerprint experts working for the MET police
What were the volunteers provided with to analyse?
A fingerprint which was inked (from a volunteer) and superimposed onto a £50
How many prints were used and how did this improve reliability?
14 were used and were checked for consistency
What equipment were P’s given?
1 of the 14 prints, fingerprint form (of suspect’s prints), CS report, fingerprint magnifying glass and a Russell comparator
When did P’s take part in the study?
In their normal working day
Where did P’s conduct the analysis and what restrictions were imposed on P’s?
In a typical analysis room with no time limit, however, no discussion was permitted
What was the high emotional context?
Murder
What was the low emotional context?
Forgery
What were P’s asked to fill out before coming to a conclusion about the mark?
Their demographic info
What were the 4 categories of classification for the fingerprints?
1) Identification, 2) Not an identification, 3) Insufficient or 4) Insufficient detail to establish identity
P’s were given a questionnaire which asked what? (Hall and Player)
Whether or not they referred to the CS infor and whether the impacted their analysis
How many out of the 70 said they read the report and how many of those were from the HEC?
57/70 read the report, 30 of those were from HEC
What percentage of the 30 HEC that read the report said that it influenced their decision?
52%
What percentage of the LEC that read the report said that it had influenced their decision?
6%
Despite what the experts reported about the influence of the report, what was found?
No significant results were found from their final opinion on the mark
What did H and P conclude from the key research?
That emotional context did no detract from the experts’ capacity to make a final decision on the print
What did Dror look into?
Top down biases
What is the bottom up approach?
Examining the ridges and patterns of a fingerprint to identify unique features of a person
When might experts use the top down approach?
If the print isn’t clear or complete
What is the top down approach?
This is when contextual effects such as type of crime or suspect are used to help with the analysis of prints
Give examples of biases which might impact fingerprint analysis
Expectancy bias, selective attention, conformity, need-determination perception, over confidence
What did Dror et al (2005) look into?
Research with 27 students and emotional context
What did Dror do?
Manipulated P’s emotions
Who were the P’s in Dror’s study?
27 students (non fingerprint experts)
How many pairs of prints were P’s given? (Dror)
96
What were shown on a screen while the students analysed the prints?
Subliminal messages saying ‘same’ or ‘guilty’
What did Dror found in terms of the high emotional cases?
That P’s were more likely to match the pairs (58%)
What percentage of low emotional cases found a match?
58%
What percentage found a match for the HEC with the subliminal messages?
66%
What did Dror conclude from this research?
That emotional context does influence analysis for non fingerprint experts
What did Miller look into/propose?
The ‘six pack’ idea
What is the ‘six pack’ idea?
That we should use the same line-up technique with fillers for hair samples and fingerprint analysis as well as for visual identification
What is the main purpose of the ‘six pack’ idea?
To produce less false positives
What did Miller give to the students?
Either 1 hair sample from 1 suspect or 5 hair samples from 5 suspects
What did Kassin suggest?
A ‘linear approach’
What did Kassin suggest in order to reduce bias in examiners?
That they should be unaware of the CSI and should examine the print context free without seeing the fingerprint of the suspect
What is ACE-V?
A scientific method for the examination of fingerprints for more structure and objectivity
What does ACE-V stand for?
Analysis, comparison, evaluation and verification
