Psychology of Witness Interviewing

Definitions

• Forensic investigation

  • Attempt to reconstruct a past event

    • Physical evidence

    • Witness evidence

• Investigations

  • Attempt to reconstruct a past event using physical evidence and witness accounts

    • Event outcomes are known

    • Challenge is to determine how the outcome came about via accurate and detailed accounts

• Intelligence gathering

  • Attempt to extract knowledge of another person about people, past and forward events, plots

    • May have some knowledge about scope

    • Challenge is to elicit as much reliable information as possible, avoiding contamination or important omissions

Memory - Challenges

• Memory accounts are

  • Prone to forgetting (loss of information)

  • Prone to distortion and error (contaminated information)

  • Prone to incompleteness (omitted information)

  • Only as reliable as the techniques used to get the information

• Memory is Constructive

  • Not a replica bit a construction rebuilt from many sources

  • Vulnerable to error suggestion and omissions (missing information)

  • Requires ‘careful handling’ of memory retrieval process

Why might cooperative interviewee leave out information they know?

• Might not associated piece of information with question that was asked

  • Not sure

  • Interviewer didn’t ask question about it

  • Forgotten and ques had just prompted their memory

  • Didn’t think it was of interest

• Study on omissions

  • 300 UK firearms officer

  • Experimentally test memory for live armed hostage scenario

    • Officers provided statements after incident

    • Highly accurate accounts but significant omissions of key details

• Important distinction: Remembering vs Reporting

  • Encoding the information but not reporting it

  • Theres a big difference between Recall and Reporting

  • Memory Recall

    • The information stored in their head

  • Witness/Intelligence information – Reporting

    • The output when tested on information

How do interviewees regulate their output

• Strategic regulation of memory

  • In any memory reporting connect the reporter will

    • Monitor potential accuracy of their memory

    • Control the output in line with goals and situational demands (what you say based on what being asked of you in a situation)

  • Two main control mechanisms

    • Withholding: ‘don’t know’ ‘can’t remembering’ omissions

    • Grain size: providing vague information (coarse grain) instead of detailed information (fine grain)

Meta memory: Insight into memory

• When asked a question answer will depend on

  • Memory knowledge

    • How much you think you can remember

    • Do you normally have a good memory

  • Monitoring effectiveness

    • Ability to successfully differentiate correct from incorrect candidate answers

    • May be biased by heuristics (ease or speed which memory the information came to mind)

  • Memory control

    • deciding to report or withhold the answer based on confidence

• Example

Suggestibility and Memory Distortions

• Memory is not an exact replica of original events

• Memory is suggestible

  • Memory can be influenced by our own biases, stereotypes, expectations and beliefs

• Memory can also be influenced by information we receive from others (misinformation effect)

  • Leading questions

  • Suggestion from another witness

  • News or social media

• Usually impossible to differentiate between original and misinformation once integrated in memory

Causes for memory errors

• Memory errors most likely to be made

  • When original memory trace is weak

    • Poor encoding of incident

      • Poor lighting

      • Confusing

  • Delay

    • Forgetting results in ‘gaps’ or hazy recollection

  • Misinformed by a co-witness

    • At the scene or subsequently (multiple re-telling and elaboration)

  • Exposure to misleading press/media

  • Misleading questions… that produce conflict or error

    • Poor interview technique (formal or informal interviews)

Episodic Memory: Associative network of memories

• Effective memory retrieval is dependent on the overlap between the encoded information and retrieval cue

  • The more cues we have, more likely we are to remember a target piece of information

  • Personal memory cues are most effective

  • A cue that related to a number of different memories won’t be effective

  • So a good interview is one which supports witness memory

Interviewing witnesses: early practical problems

• Traditionally a high frequency low status activity

  • Perceived as routine, low level skill largely uninteresting

  • Not seen as important

IW: early practical problems - Fisher 1987

• Witness interviewing by experienced officers

  • All requested a free narrative but interrupted on average after 7.5 seconds – telling you, your not really listening

  • Officers were agenda driven

  • Witnesses who went off-tract interrupted

  • Questions followed case theory, were directive, disrupted recall, failed to follow up potential leads

  • Many asked formulaic question incompatible with the witnesses effort to represent the incident

  • Officers used formal stylised language, technical terms and jargo

  • Question were rapid fire and pressuring

• Problems identified

  • Closed interview

    • Focus on question asking rather than cuing memory

    • Misleading questions

    • Inadequate for quantity and quality recall

    • Lack of consistency between interviews

    • Inadequate for both interviewer and the interviewee

Cognitive Interview - Original cognitive interview (Fisher 1984)

• Report everything instruction

  • Encourages witnesses to report everything they remember without any editing

  • Even if they think the details aren’t important

  • Intended to discourage the witness from holding back any information (promoting full disclosure)

  • Instructed to avoid guessing or making things up

  • Maximises the completeness of the report

  • Enables the interviewer to gain a more complete picture

• Mental reinstatement of context

  • Facilitates the features overlap between the event and retrieval environment

  • Encourages a witness to mentally recreate the psychological and physical environment which existed at the time of the event

    • Description of environment, people, smells feelings and reaction to events

• Recalling events in a variety of different orders

  • E.g. Reverse order

  • Discourages use of script knowledge

  • May facilitate the recall of script inconsistent information

• Change perspective technique

  • Ask for recall from variety of perspective

    • In the shoes of another witness

  • Forces change in retrieval description, allowing additional information to be recalled from new perspective

  • Extreme care recommended in the use of this technique

    • May misinterpret the instructions of adopting someone else’s perspective as an invitation to fabricate an answer

Cognitive Interview - Enhanced CI

• Later focus: importance of Rapport and Social Facilitation

  • Transfer control of the account to the witness

  • Original CI: 25% - 35% more correct information

  • Enhanced CI: 45% more correct information

• Current practice

  • Currently ‘gold standard'’ witness interview

  • Recommended good practice in many countries throughout the world

  • Some problems remain

    • Time-consuming

    • Resource intensive

    • Not a suitable form of interview in certain circumstances

International Witness Interviewing

• UKS and USA included the cognitive interview in the national evidence-based guidelines

• Uk: PEACE is in national framework

• Standard witness interview in most of the world

  • No/little opportunity for free narrative

  • Overuse of closed and direct questions

  • Use of leading questions

  • Control over witness

  • No assistance to enhance memory recollections

    • Calls into question the quality of witness statements