Section two

• What is section two of crime

  Forensic evidence
• What is inter observer consistency

  Difference between finger print examiners
• What is intra observer consistency 


  Difference in one examiner over time
• What is a cognitive bias

  Where someone is not accurate in the way they think about something.
• What is conformity effect

  If asked to agree or disagree with other people someone might not challenge a previous decision
• What is need determination perception

  Strong desire to solve a crime then they may come up with an incorrect match.
• What is over confidence bias

  Experts may believe they are always right.
• What is expectancy bias

  If the expert anticipates the outcome
• Evidence for cognitive bias

  Dror - examined expectancy bias
• How did dror study expectancy bias

  Used 5 finger print analysts. all had same experience (17 years). They were studied for 12 months in every day work. Asked to examine a pair of fingerprints taken from a crime scene. All of them had previously seen the fingerprints and recorded them as a definite match. They were told they were wrongly identified and the expectation was no match. 4/5 changed their decision.
• How might emotional states change bias

  If there is a high emotion case people will want to solve it.
• Evidence for emotional states.

  Dror- studied 27 university students.

  they were given 96 pairs of fingerprints . They were related to crimes both low and high emotion. Photos of the crime were also given to reinforce the emotion. Participants had to decide if they were a match or not.
• What did dror find in relation to emotional state and bias

  High emotion cases led to a 58% match and low emotion cases were 49%
• What are the issues with drors study into emotional context

  The participants were students and so had no training.
• What is the key research

  Hall and player
• Aim of HP

  Does the written report of a crime affect the fingerprints expert of interpretation of a poor quality mark. are they emotionally affected.
• What method of HP

  Field experiment and independent measures
• What was the IV of hall and player

  Low or high emotion case
• What was the DV of HP

  if it was a match

  if they had read report

  if they were affected by report
• Sample of HP

  70 finger print experts from metropolitan police fingerprint bureau. Had 3months - 30 years experience. Self selected
• Procedure of hall and player

  Took place in their own work space and own time. Weren’t allowed to discuss their decision or fingerprint. They were assigned to either high or low emotion. all given an envelope containing either a high or low report and a printed finger print from crime and other prints to match it to. After they had finished they completed a questionnaire asking where they worked how much experience they had and if they’ve presented in court. They were also asked If they read the report and if it affected them.
• What was the high emotion case in hall and player

  Allegation of murder. The same as low emotion but then the suspect fired two shots and decamped.
• What was the low emotion case in hall and player

  Allegation of a forged £50. The forgery was spotted and the person ran away.
• Results of hall and player

  57/70 read the report.

  30/57 read the high emotion.

  52% of high emotion felt it influenced their decision whereas 6% felt they were influenced in low emotion
• Hall and player conclusions

  experienced experts were less affected

  emotion of a case can influence a decision
• Application 1

  Linear sequential unmasking
• Application 2

  Blind testing