the collection and processing of forensic evidence

• what is the background theory here?

  1. madrid bomber brandon mayfield an american muslim and how he was mistaken to be madrid bomber when he never even went to madrid all because of an error that occured analysing his fingerprint leading to 4 people doing the same mistake
• what is a latent print ?

  print collected straight from the crime scene
• how are fingerprints analysed ?

  through humans matching two prints together
• what did drors study tell us?

  he showed us that when decisions are made about fingerprints in highly emotional context it increases the liklihood of a match decision being made

  he used university students and found that when crime involves a high context crime they are more motivated to find the criminal behind it

  this shows how the emotional context creates bias
• what was the aim of hall and players study?

  they designed an experiment to test the effect of context on fingerprint analysis by experts
• research methods?

  • lab experiment designed to be as naturalistic as possible
  • in their work place
  • new scotland fingerprint bureau
  • even tho it was naturalistic it was an artificially intelligent task
• iv and dv

  • iv>whether high or low context crime was given
  • dv>whether the p read the crime scene report or not
  • result of analysis
  • whether they would be confident or not to present the evidence in court
• sample?

  • 70 fingerprint experts
  • mean experience 11 years
• what was the procedure?

  1. used a volunteers right forefinger and reimposed the image on a 50 pound note
  2. 14 copies were made and compared to ensure consistency
  3. volunteers were randomly assigned in groups of eight
  4. they were told they can come and go as they pleased and can talk amongst each other as long as its not about the fingerprint
  5. low emotional context was about an allegation of forgery because it was a victimless crime
  6. whereas the high emotional context was a murder crime
  7. they were told that it was a right forefinger
• findings?

  • aim 1 > only 57 out of 70 read the crime report
  • 17% of high context were confident to present in courtroom and 20% of low context
• conclusion

  • emotional context affects a fingerprint analysis but does not have any actual effect on their final decision
  • different types of crime has not actual significance
• Explain why Hall and Player’s study did not support the reliability of Dror’s study into emotional context as a biasing factor in the analysis of fingerprints?


  Dror found that university students are affected by the context when the case involves harm than minor offences. However, Hall and Player showed that the context of the crime does not affect the decisions – lacks external reliability. 
• The contribution made by the key research to our understanding of the impact of psychology on the collection and processing of forensic evidence


  Shows that novices are affected by context when analysing finger prints whereas experts are not affected by context. This contributes to the importance of training finger print analysts to ensure the most accurate result. 
• introduction part A 


  Cognition is a mental process that includes perception, memory, reasoning and making judgements. It is important that forensic experts guard against factors that lead to predictable errors in making judgements when collecting forensic evidence. However, motivating factors most often exist when police and others investigate crimes that have high emotional context such as murder and violent attacks. The increased level of emotion produces a strong desire to find the offender. Hall and Player aimed to research these motivating factors with finger print experts. 
• Emotional context can affect the fingerprint experts thinking, emotional context may be more influential
• 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