Graham Davies

Week 4

Enhancing police interviewing of witnesses

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

Hypnotic Interview(Reiser, 1990)

• focussed attention (drawing pin)

• relaxation (imagery)

• distancing (TV screen)

• regression (context induction)

• suggestion (perfect recall)

Success – The LAPD Study(Reiser, 1980)

• 374 ‘dead’ cases

• witnesses re-interviewed under hypnosis

• 54% new information

• 16% cleared up

Reiser’s ‘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)

Predictions of Cybernetic Model

• More complete recall under hypnosis

• Fewer errors

• Reduced impact of leading questionsand post-event misinformation

A facet of the wider debate as to whether hypnosis is an altered state of consciousness.

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)

Cognitive explanations for positive findings from

hypnosis

• Impact of cognitive reinstatementinstructions (Timm, 1981)

• Criterion shift (Dywan & Bowers,1983)

• Hypermnesia (Cooper & London,1973)

Social explanations for positive findings from

hypnosis

• Compliance and belief (Wagstaff, 1999)

• Relaxation and surrendering control

(Wagstaff, 1982)

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)

The Backlash

• Hypnotic testimony now

banned in 25 States

• People v. Shirley (1982)

• All three major organisations for

hypnotists now ban use with

witnesses

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)

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)

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)

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.)

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.

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

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

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)

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

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)