Theories of Interviewing witnesses

The Theories/Studies

1. Bruce et al (1988) - The importance of external and internal features in facial recognition

2. Loftus et al (1987) - Weapon Focus 3. Fisher and Geiselman (1992) - The Cognitive Interview

The main approach in this area is Cognitive psychology. How we process information and are able to recognise and remember it accurately is important for witnesses of crime. This area highlights factors that may influence the accuracy of such information.

1. Bruce et al (1988) - The importance of external and internal features in facial recognition

Background:

Cognitive psychologists have done a lot of research into how we recognize faces. Loftus has

shown again and again how people’s memories are reconstructive – we “invent” our memories from SCHEMAS (stereotyped ideas) and we are very influenced by leading questions. Even the difference between asking a witness to start by remembering the eyes or the ears could have a huge effect on the face they come up with.

One of the great breakthroughs in Forensic Psychology has been the FACIAL COMPOSITE technique. This involves helping witnesses put together the image of a face from the different components a face is made from – choosing the right nose from a selection of noses, the right eyebrows from a selection of eyebrows, etc. The first successful facial composite was IDENTIKIT, developed in the 1940s by the Los Angeles police. This was developed in England into PHOTOFIT, which used more realistic photographs rather than drawings. The latest computer packages, like E-FIT, help witnesses pick facial features from huge

databases of faces.

Aim: To Investigate which is more recognisable, internal or external features

Method: Three Lab experiments.

Participants, details & results:

Experiment 1:

Experiment 2:

Conclusions:

Evaluation: Issues Evaluation: Debates

2. Loftus et al (1987) - Weapon Focus

Weapon focus refers to the concentration of a witness’s attention on a weapon which results in them having difficulty recalling other details of the scene and identifying the perpetrator of the crime.

Previous research carried out has shown that people fixate their gaze for longer, faster and more often on unusual or highly informative objects.

Aim: To Provide support for the ‘weapon focus’ effect when witnessing a crime.

Type of Data: Quantitative Data

Method: A Lab experiment.

Participants & Procedure:

Results:

Conclusions:

Evaluation: Issues Evaluation: Debates

3. Fisher and Geiselman (1992) - The Cognitive InterviewAim: To test the cognitive interview (CI) in the field.

Method: Field Experiment with actual interviews of real witnesses by serving police detectives.

Participants & Procedure:16 detectives with at least 5 years’ experience, Dade County

Results: The CI trained detectives, collected 47% more info than before and 63% more than the untrained detectives. No difference in accuracy across conditions and CI took longer.

What is a Cognitive Interview?

The Cognitive interview technique (CI) is based largely on the work of

Loftus and other psychologists, following their theoretical work into

memory (remember her AS Core Study?).  It is designed to take

account of well known cognitive functions and avoid any chance of leading the

witness.

The CI involves the interviewer giving a set of instructions to the witness to

reinstate the context of the original event and to search through memory

by using a variety of retrieval methods.

There are 4 basic principles:

1. Interview similarity – memory of an event is enhanced when the psychological environment at the interview is similar to the environment at the original event. The interviewer should therefore try to reinstate in the witness’s mind the external (weather), emotional (fear) and cognitive (relevant thoughts) features that were experienced at the time of the crime.

2. Focused retrieval – The interviewer is to generate focused concentration. There should be no interruption to the chain of thought and plenty of encouragement to try hard.

3. Extensive retrieval – Witnesses should be encouraged to make as many retrieval attempts as possible. Even if they say they cannot remember, they should be encouraged to try another angle, eg. imagine the scene from another viewpoint.

4. Witness-compatible questioning- Events are stored and organised uniquely for each witness. Successful retrieval therefore reflects how compatible the questioning is with the witness’s unique mental representation. Interviewers should be flexible and alter their approach to meet the needs of each witness.

Conclusions:

Evaluation: Issues Evaluation: Debates

Summary: Interviewing witnesses

The work of Bruce and others shows that the old ways of constructing

photofits relied on a false idea of how we recognise faces. Her research is

leading to seeing face reconstruction as a holistic process with much more

satisfactory results.

It has been known for some time that if a weapon is involved in a crime

then a witness is likely to be less accurate at identifying a suspect, as the

shock of seeing a weapon will dominate over recall of the suspect’s facial

features.

When interviewing a witness it is important not to lead them in any way,

yet prompts can help recall immensely. A cognitive interview approach allows

the witness to improve recall by reconstructing the event in their mind,

inducing smells, feelings and taking different perspectives on the event.

Comprehension questions for interviewing witnesses

1. Bruce et al (1988) - The importance of external and internal features in facial recognition

What are the differences between internal and external features?

What are distracter faces or foils?

What conclusions can be drawn from Bruce et al.’s study?

2. Loftus et al (1987) - Weapon Focus

What is the Weapon Focus effect?

Weapon focus refers to the concentration of a witness’s attention on a weapon which results in them having difficulty recalling other details of the scene and identifying the offender of the crime.

What criticisms can be made of Loftus’ sampling frame?

What controls did Loftus use in this experiment?

Why it is important that the students were told the study was into leading questions?

3. Fisher and Geiselman (1992) - T he Cognitive Interview

Why did Fisher record interviews from before the detectives were CI-trained?

What is meant by blind-testing and why is it a good thing?

What other factors might have affected the results, apart from Fisher’s IVs?