Eliciting Information from Sources and Suspects
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ELICITING INFORMATION FROM SOURCES AND SUSPECTS Dissertation zur Erlangung des Doktorgrades der Philosophischen Fakultät der Christian-Albrechts-Universität zu Kiel vorgelegt von Lennart May Kiel, 21.07.2017 Erstgutachter: Prof. Dr. Thomas Bliesener Zweitgutachter: Prof. Dr. Günter Köhnken Tag der mündlichen Prüfung: 20.11.2017 Durch den Prodekan, Prof. Dr. Elmar Eggert, zum Druck genehmigt: 24.11.2017 Abstract Gathering information in human interactions is a critical aspect for police and intelligence interviewers. However, quite recently and rather slowly researchers have started to focus on using available information in order to collect case-related information in such interactions. This thesis advances this line of research by conducting three studies on how to use available information to elicit new information from sources and suspects. Two of the studies were about the Scharff-technique and one was about the Strategic Use of Evidence (SUE)-technique. Study I compared two combinations of the Scharff tactics and the Direct Approach. Participants (N = 93) took the role of a source and were instructed to strike a balance between not revealing too little or too much information. Overall, the sources in both Scharff conditions revealed more new information, perceived the interviewer to hold more knowledge, and found it more difficult to understand the interviewer’s information objectives, compared to the sources in the Direct Approach. The sources interviewed by the Scharff conditions underestimated how much new information they revealed, whereas the sources interviewed by the Direct Approach overestimated the amount of new information revealed. Study II examined two ways of introducing the presentation of the known information when using the illusion of knowing it all tactic of the Scharff-technique. Again, participants took the role of a source but without having the chance to reveal information. In two separate experiments (each N = 60), the sources’ perceptions of the interviewer’s knowledge and knowledge gaps were mapped. This study found that by just starting the presentation of the known information made the sources believe the interviewer had more knowledge and they searched less actively for gaps in the interviewer’s knowledge, compared to when the interviewer used an extreme convinced introductory statement about his or her case-related knowledge. Study III tested two different ways of eliciting and disclosing statement-evidence inconsistencies using the SUE-technique against an early disclosure of the evidence. Participants (N = 88) performed a mock crime and were instructed to claim innocence. Both SUE conditions resulted in more inconsistencies and the suspects overestimated the interviewer’s knowledge to a higher extent than the Early disclosure condition. However, only the non- judgemental version of the SUE-technique resulted in more new information (vs. the Early disclosure condition) and created a more fostering interview atmosphere (vs. the confrontational version of the SUE- technique). In line with the three studies, this thesis developed an interviewing framework consisting of a conceptual and tactical tier. The conceptual tier explains the cognitive and verbal processes of the sources/suspects in interviews and the mechanisms behind the Scharff and SUE tactics. The tactical tier includes the Scharff-technique and SUE-technique and shows ways in order to influence the sources’/suspects’ perceptions and verbal behaviours. Overall, the developed two-tier interviewing framework can help to train practitioners and initiate further research. Keywords: HUMINT interview, Suspect interview, Information gathering, Information elicitation, Scharff, Strategic use of evidence Table of Contents INTRODUCTION ............................................................................................................ 1 Defining the Scope of this Thesis ................................................................................ 2 Research on Suspect Interviewing ............................................................................... 3 Research on HUMINT Interviewing ............................................................................ 9 Two-Tier Interviewing Framework ............................................................................ 14 Conceptual Tier ......................................................................................................... 14 Tactical Tier ............................................................................................................... 22 Scharff-technique ....................................................................................................... 23 Strategic Use of Evidence (SUE)-technique .............................................................. 28 SUMMARY OF THE EMPIRICAL STUDIES ............................................................. 32 General and Specific Aims ........................................................................................ 32 Study I ........................................................................................................................ 33 Study II ....................................................................................................................... 36 Study III ..................................................................................................................... 40 GENERAL DISCUSSION ............................................................................................. 43 Scharff Tactics ........................................................................................................... 44 Explaining the Scharff Tactics with the Conceptual Tier .......................................... 49 SUE Tactics ................................................................................................................ 51 Explaining the SUE Tactics with the Conceptual Tier .............................................. 55 Extending the Conceptual Tier for Training and Research Purposes ........................ 58 Ethical Considerations ............................................................................................... 62 Limitations and Further Reflections ........................................................................... 64 Conclusions ................................................................................................................ 66 REFERENECES ............................................................................................................. 67 ACKNOWLEDGEMENTS ............................................................................................ 80 APPENDICES ................................................................................................................ 81 A Publications ............................................................................................................ 81 B German Summary ................................................................................................. 121 C Curriculum Vitae .................................................................................................. 133 INTRODUCTION For several decades, suspect interviews have been the focus of psycho-legal research. As a result of this, researchers have identified the risk factors of false confessions and have developed alternatives on how to better conduct suspect interviews (for an overview see Bull, 2014). However, research to date has provided few specific “tools” on how to exactly gather information from suspects. The research on human intelligence (HUMINT) gathering is still at an early stage, and therefore hardly any “tools” are available in the field of intelligence interviewing. This thesis sets out to develop an interviewing framework for eliciting information from suspects and sources. For this purpose, the research presented here employed an experimental approach, which is useful for examining interviewing interactions in a controlled setting (Meissner, Hartwig, & Russano, 2010). #ONCEPTUALTIER )NTERVIEWEES@COGNITIVEANDVERBALPROCESSES 0ERSPECTIVETAKINGBYTHEINTERVIEWER 4ACTICALTIER 3CHARFF TECHNIQUE 35% TECHNIQUE Figure 1. The two-tier structure of the interviewing framework developed in this thesis. This thesis starts with a brief overview of the current research on suspect and HUMINT interviewing. Next, the interviewing framework developed in this thesis is presented. Figure 1 illustrates this interviewing framework which consists of a conceptual and tactical tier, drawing inspiration from Granhag and Hartwig’s (2015) model. These two tiers set the stage for this thesis. Broadly speaking, the conceptual tier describes general assumptions on the suspects’/sources’ cognitive and verbal processes. By taking the interviewees’ perspective the interviewer can use these assumptions strategically in order to obtain new information in the interview. The tactical tier includes practical ways to reach sub-goals during the interview. In this thesis, two sets of tactics are examined: the Scharff-technique and the Strategic Use of 1 Evidence (SUE)-technique. After introducing the developed interviewing framework, the empirical studies of this thesis are summarized. Then, the findings are discussed in the scope of the tactical and conceptual tier of the interviewing framework. Finally, further considerations on the conceptual tier will be discussed for training and research purposes. Defining the Scope of this Thesis Gathering information from humans is a critical