Interviewing suspects and witnesses:

1. Interviewing suspects and witnesses:

2. Problems in interviewing suspects and witnesses: Interviewing witnesses may distort their evidence. Interview techniques are not always optimal for extracting information from witnesses. Interviewing suspects may lead to false confessions.

3. The Cognitive Interview technique: (Geiselman et al 1984): Based on psychological principles: (a) Tulving and Thomson's (1973) "Encoding Specificity Principle" - items are encoded together with features of the context within which they occurred. Compatibility (overlap) between encoding and retrieval contexts facilitates recall. (b) May be several retrieval paths to an encoded event, so that information inaccessible by one retrieval cue might be accessible with a different cue (Tulving 1974; Anderson and Pichert 1978). 

4. Original Cognitive Interview's components: (a) Context reinstatement - (i) emotional aspects ("How were you feeling at the time?") (ii) perceptual features ("picture the room: how did it smell, what could you hear?") (b) Recalling events in a variety of orders. (c) Mentally changing perspectives (e.g. own, victim's, suspect's, another witness'). (d) Trying to recall every detail they can remember, no matter how apparently trivial. (Details may lead to recall of addtional, more relevant, information). 

5. Enhanced Cognitive Interview: "Cognitive" techniques plus "communication" techniques: (a) Open-ended, non-leading questions - e.g. "tell me everything you can remember about the robber". (b) Social communication techniques, e.g. rapport building, not interrupting witnesses, timing questions.

6. Empirical evalautions of the Cognitive Interview: Typically increases correct recall by 25-50% compared to standard interview.

7. (a) Geiselman, Fisher, MacKinnon and Holland (1985): Students watched 4-minute film of a violent crime. Interviewed 48 hours later by either: (i) Standard police interview; (ii) Hypnosis; (iii) Cognitive Interview. More correct statements in CI and Hypnosis conditions than in standard Police interview. No difference between hypnosis and CI. Similar error rates in all conditions - suggests hypnosis and CI did not improve recall by increasing subjects' readiness to say anything at all, correct or not. CI quicker and easier than hypnosis.

8. (b) Geiselman, Fisher, MacKinnon and Holland (1986): Staged classroom interruption. Students interviewed using CI were more resistant to leading questions about a backpack's colour than were students given a standard interview. (c) Fisher, Geiselman and Amador (1989): CI-trained detectives produced 63% more information in interviews than did non-CI-trained detectives.

9. (d) Kohnken, Milne, Memon and Bull (1994): Meta-analysis of 32 experiments (1200 subjects, 2500 interviews). CI increased amount of information recalled by 36%. Number of incorrect details recalled increased by 17%. Significantly increased recall of both correct and incorrect items. However, the mean accuracy rate (proportion of correct details recalled relative to total number of recalled details) was similar to the standard interview (84% for the CI and 82% for the standard interview).

10. (e) Mantwill, Kohnken and Aschermann (1995): Is effectiveness of CI limited to highly episodic information? Tested recall of experienced and inexperienced blood-donors for events in a videotape of blood-donation. CI enhanced recall; no effects of familiarity.  

11. Effectiveness of CI with children: Limited meta-memory skills, problems with source monitoring. Koehnken, Milne, Memon and Bull (1994): Meta-analysis of effectiveness of CI for children. Increases amount of correct details and false information recalled: overall accuracy rate remains constant. "Recall in reverse order" and "change perspective" instructions confuse children.

12. Effectiveness of CI with the elderly: Prone to source memory errors, hence false memories. Dornburg and McDaniel (2006): 65-87 year-olds read story about a couple's relationship, expecting to be questioned about their emotional reactions to it. 3 weeks later: unexpected non-interactive CI or standard interview. 3 attempts at recall. CI improved recall, without impairing accuracy or affecting confidence ratings. In CI group, decreased frontal scores were associated with increased incorrect recall.

13. Practical problems with CI: Kebble, Milne and Bull (1999):Survey of British police officers suggested CI was too time-consuming. "Change order" and "change perspectives" rated as least useful components of CI. Clifford and George (1996):British police reluctant to use the "change order" and change perspective" instructions; relied on "context reinstatement". Boon and Noon (1994):only the "recall everything" instruction was widely adopted by police. Kebbell et al. (1999): police officers who used the CI preferred the "recall everything" instruction.

14. Davis, McMahon and Greenwood (2005): Compared 3 types of interview: ECI, MCI (shortened CI, with above mnemonics replaced by additional free-recall attempts), SI (structured interview without cognitive mnemonics). No. correct items recalled: ECI = MCI > SI No. incorrect items recalled: ECI = MCI = SI Accuracy rate: ECI = MCI = SI "Report eveything" and "context reinstatement" are the crucial CI components. MCI elicited 87% of ECI information, but was 23% faster.

15. Effective components of CI: Milne and Bull (2002): Children aged 5-6, 8-9 and ug's viewed video of an accident. Interviewed 48 hours later, with either (1) context reinstatement, (2) change perspective, (3) change order, (4) report everything, (5) report everything/context reinstatement combination (RE/CR), (6) control instruction to ‘try again’. (1) - (4) were equally effective but no better than (6). RE/CR produced more correct recall than individual mnemonics. No effects of age group on effectiveness of the various instructions.

16. Marsh, Tversky and Hutson (2005): Effects of post-event rumination on recall. After viewing a violent film, subjects either talked about their emotional responses to it; gave a factual account; or did unrelated tasks. Talking about emotions led to greater subjectivty and more errors in free recall. Differences were minimised by tests providing more retrieval cues.

17. False confessions as a major cause of miscarriages of justice: Borchard (1932): False confessions elicited by police pressure or simply under the influence of “a stronger mind upon the weaker” were very damning. Brandon and Davies (1972): Defendants often mentally-deficient, juveniles or psychologically vulnerable or disturbed, i.e. abnormally susceptible to suggestion. Bedau and Radelet (1987): 49 of 350 cases (14% )involved false confessions, mainly due to coercion.

18. Reasons for False Confessions (Gudjonsson 1992): 1. Morbid desire for notoriety. 2. To relieve guilt for previous transgressions. 3. Schizophrenia. 4. Coerced compliant -confess to get out of custody, to stop the police interrogating them, or to cope with the pressures of the situation. Will retract their confession as soon as they are out of the situation. 5. Coerced internalised - come to believe during police interrogation, that they actually did the crime, even though they have no memory of it. May come to believe their false confession, for some time.

19. Coerced internalised - Due to (a) amnesia at time of crime (amnesia or alcohol-induced memory problems), so no clear recollection of what they were doing at the time of the crime. (b) memory distrust - come to distrust initial clear recollection of not having committed the crime. Interrogation produces sufficient self-doubt and confusion to cause them to adjust their perceptions of reality.

20. Predisposing factors in coerced-internalised confessions (Ofshe 1989): (a) interrogator stated, with great confidence, his belief in the suspect’s guilt. (b) suspect was isolated from contradictory people or evidence. (c) lengthy interrogation. (d) interrogator repeatedly reminded suspect of his memory problems or mental disorder. (e) interrogator induced fear about consequences of repeated denials. (f) personality factors - good trust of people in authority; lack of self-confidence; heightened suggestibility.

21. Reality monitoring and false memories: Deese-Roediger-McDermott (DRM) paradigm: listening to thematically-linked word list results in false recall of similar words not actually presented. Effect higher for words (70-80% false recognitions) than pictures (30%) but depends on how images are generated. Foley, Wozniak and Gillum (2006): Source monitoring framework - false memory effects consistent with "impoverished encoding" and "distinctiveness heuristic". Guided imagery may impair source monitoring abilities.

22. Conclusions: Cognitive interview increases amount recalled, without compromising accuracy. Critical components are "context reinstatement" and "recall everything". Memory is labile and open to many influences: essentially an inferential, reconstructive process. Source monitoring is easily influenced, especially under interrogation conditions, leading to risk of coerced-internalised confessions.

23. He thinks he didn't do it, but we can persuade him otherwise.