Hall & Player (2008) Will the introduction of an emotional context affect fingerprint analysis and decision-making?

• background about MET police

  In UK, Metropolitan Police Fingerprint Bureau gives fingerprint experts assigned to a case a copy of the crime scene examination report which provides details of nature of crime (but no photographs), so examiner making decisions about the match of prints is exposed to potentially high-emotion background material
• background for study

  Dror found that the emotional context of can impact upon decision-making (research had non-expert sample)
• the aim was

  to investigate whether:

  1. the fingerprint experts were emotionally affected by the case details in the report

  2. emotional context would bias the judgements of expert analysts (like in Dror et al's study with students)
• the sample was

  70 fingerprint experts working for the MET Police Fingerprint Bureau, experience ranging from less than 3 months to over 30 years, mean of 11 years. all volunteers who responded to request take part in an experiment. data collected were recorded anonymously using a unique reference number for each expert
• the research method was

  laboratory experiment (but designed to be as naturalistic as possible), using independent measures design
• stages of fingerprint analysis

  four-stage process of examining a latent print

  ACE-V: Analysis, Comparison, Evaluation, and Verification
• two conditions to which participants were allocated

  1. low emotional context - allegation of forgery (victimless crime with minor sentence)

  2. high emotional context - allegation of murder (crime with clear victim and severe sentence)
• low emotional context report

  suspect entered premises and tried to pay for goods with a forged £50 note. the forgery was spotted by cashier. suspect then decamped
• high emotional context report

  suspect entered premises and tried to pay for goods with a forged £50 note. the forgery was spotted by cashier. suspect then fired two shots before decamping
• IV was

  emotional context of report (low/high)
• DV was

  1. whether analyst felt affected by the context-creating scenarios

  2. whether this affected their final decision about the fingermark
• decisions/judgements made on the latent mark by analysts

  1. identification (match)

  2. exclusion (not match)

  3. insufficient (not enough detail to undertake a comparison)

  4. inconclusive (insufficient detail to establish identity; some detail in agreement but not enough to individualise)
• individualise

  being able to isolate a particular suspect by determining that the latent print could have only come from that person
• procedure


  a fingerprint (right forefinger) from a volunteer was inked onto paper and then scanned and superimposed onto an image of a £50 note. The background image of the note obscured the ridge detail and therefore the fingerprint was of poor quality (latent mark was only just identifiable). separate sample of experts confirmed mark was of poor quality and an ambiguous match to a set of 10 prints from the donor. each participant was given an envelope with a test mark card (with sheet saying it was from right forefinger), the 10-print fingerprint, scene examiner's report, fingerprint magnifying glass and Russell Comparator (optical magnifier unit for comparing two images) - it was a typical case report except for the advice about finger (included for speed). participants were randomly assigned to groups of 8 and asked to treat experiment and task like an ordinary case and normal day, moving around and talking to each other (but not about experiment or fingermarks). there was no time limit. after analysis, they were asked to make judgement about print as they would normally, and asked to elaborate on findings, providing observations and opinions. via feedback sheet, they were asked whether they had referred to the crime scene report prior to assessment of marks - if they done so, they were then asked whether they felt the info had affected their analysis
• results

  57/70 participants read the crime scene examination report before examining the prints. 52% of the 30 participants from high emotion context who read the report said they were affected by the info read (only 6% in low-emotion) - indicates that there's a relationship between the type of context and the perceived effect on experts. around 20% of participants in both groups felt confident in presenting the evidence in court (20% low, 17% high) - relationship wasn't significant.
• conclusion

  1. emotional context affects experts' feelings but doesn't influence the final outcome of their analysis (due to no difference being observed between high and low emotion contexts)

  2. experienced fingerprint experts are better are doing analyses in a detached manner than non-experts (compared to Dror et al's findings)