Graham Davies

1
Graham Davies

• Week 4
• Enhancing police interviewing of witnesses

2
Psychology and Police Interviewing

• Interviews with witnesses still remain the major
  source of information in solving crime
• Psychologists have been increasingly called upon
  to refine existing procedures for interviewing
  both suspects and witnesses
• Work on false confessions(Gudjonnson)hypnotic
  and cognitive interviews

3
Hypnotic Interview(Reiser, 1990)

• focussed attention (drawing pin)
• relaxation (imagery)
• distancing (TV screen)
• regression (context induction)
• suggestion (perfect recall)

4
Success The LAPD Study(Reiser, 1980)

• 374 dead cases
• witnesses re-interviewed under
  hypnosis
• 54 new information
• 16 cleared up

5
Reisers Cybernetic Model of Memory

• All information is stored
• All is potentially available
• Hypnotic procedures have no impact on memories
• The mind is like a videotape machine, everything
  is recorded, perhaps at a subconscious level and
  stored in the brain, but available under
  hypnosis
• 
  (Reiser, 1980)

6
Predictions of Cybernetic Model

• More complete recall under hypnosis
• Fewer errors
• Reduced impact of leading questions and
  post-event misinformation
• A facet of the wider debate as to whether
  hypnosis is an altered state of consciousness.

7
Research on Hypnosis and Memory

• No impact on lab tasks
• (Mingay, 1987 Erdelyi, 1992)
• Limited realism?
• (Yuille McEwan, 1985)
• Confidence and leading questions
• (Putnam, 1979)
• But isolated positive findings, particularly with
  more realistic settings (Yuille Kim, 1987)

8
Cognitive explanations for positive findings from
hypnosis

• Impact of cognitive reinstatement instructions
  (Timm, 1981)
• Criterion shift (Dywan Bowers, 1983)
• Hypermnesia (Cooper London, 1973)

9
Social explanations for positive findings from
hypnosis

• Compliance and belief (Wagstaff, 1999)
• Relaxation and surrendering control
• (Wagstaff, 1982)

10
Hypnosis More than the sum of its parts ?

• High belief in hypnosis aiding memory
• (Orne, 1983 - 96)
• High impact on trial outcome
• (Wagstaff et al., 1992)
• People vs Kempinski (1980)
• False memory production
• (Orne, 1979)

11
The Backlash

• Hypnotic testimony now
• banned in 25 States
• People v. Shirley (1982)
• All three major organisations for
• hypnotists now ban use with
• witnesses

12
HOME OFFICE GUIDELINES(1988)

• Only qualified personnel
• Informed consent
• No investigators present
• Videotape of whole interview
• only when all other methods have failed
• the impact of R v Browning (1994)

13
The Cognitive Interview

• An approach to interviewing grounded in theories
  of memory function
• Simple ideas but widely taken up by the police
  world-wide
• Developed by Geiselman Fisher (1984)

14
Theoretical Assumptions

• Memory as a bundle of features
• retrieval involves feature overlap
• (Bower, 1967)
• Memories may be accessed via
• explicit but multiple pathways.
• Inappropriate cueing will lead to
• retrieval failure (Tulving, 1974)

15
Mnemonic techniques of the cognitive interview

• feature overlap induced by
• - mental reconstruction of environmental/
• personal context
• - report all details instruction
• retrieval paths exploited by
• - recounting event in different orders
• - reporting events from a different
• perspective
• Plus explicit mnemonics (alphabet searching
  resemblance to known person etc.)

16
CI vs Standard Police interview and
hypnosis(Geiselman et al. 1985)

• Police training film of violent crime
• Experienced police officers vs CI trained
  college student
• interviewers
• 40 increase in correct information and no
  effect on
• errors
• No difference between hypnotic and CI
  interviews.

17
The enhanced cognitive interview(Fisher
Geiselman, 1992)

• Much greater emphasis upon communication
  skills,
• less on memory
• Rapport building and interviewer support
• Witness-compatible questioning
• Focused retrieval (imagery)
• Perspective change and report all details
• de-emphasised

18
Field study on CI Effectiveness(Fisher et al.
1989)

• Tape recorded interviews by 7 detectives
  investigating crime on the street
• Constant interruptions of witnesses
• Formulaic interviews
• Specific questions
• After training in the Enhanced CI
• Increase in information from 34 115
• 94 of ascertainable facts corroborated

19
Later research emphasised the importance of
appropriate controls

• Earlier studies flawed number of accounts not
  controlled
• Importance of motivation and n questions
• But positive effects still present
• (Kohnken et al. 1994)

20
Criterion shift or improved accuracy ?

• Meta-analysis of published studies
• (Kohnken et al. 1999)
• 35 increase in correct information but
• only 18 increase in errors from a low base

21
Which components are the most important ?

• context reinstatement most
• reliable
• but least used by serving officers
• (Memon et al. 1995)
• children may have difficulties
• with some components (Saywitz
• et al. 1995)
• Reinstatement may be inadvisable
• in cases of trauma
• (Geiselman, 1995)