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Two Key Problems for the Legal System

Who? What? When? Using a Timeline Tool to elicit details of complex witnessed events Lorraine Hope University of Portsmouth Rebecca Mullis University of Portsmouth Fiona Gabbert University of Abertay. Two Key Problems for the Legal System.

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Two Key Problems for the Legal System

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  1. Who? What? When?Using a Timeline Tool to elicit details of complex witnessed eventsLorraine HopeUniversity of PortsmouthRebecca MullisUniversity of PortsmouthFiona GabbertUniversity of Abertay

  2. Two Key Problems for the Legal System • When crimes take place involving multiple perpetrators, individual perpetrators may admit presence at the scene – particularly if identified - but dispute participatory acts • Significant problem for prosecution is the witness is unable to provide an account of who did what (Roberts, 2003) • Memory errors for actions or the sequence of events in an incident may discredit an otherwise reliable witness • particularly if other evidence, such as CCTV footage, contradicts their account of how an event unfolded

  3. Improving recall of order, actions and involvement • Mental Context Reinstatement • Core component of the Cognitive Interview • Is there a way to further capitalize on the way episodic memory is organized? • Explicit emphasis on temporal order via extra reinstatement of temporal context? • Or a task which implicitly facilitates recall in temporal order?

  4. Temporal Context in Memory • Temporal-contextual retrieval processes • Episodic memory system “stores information about temporally dated episodes or events, and temporal-spatial relations among these events” (Tulving, 1983) • Evidence for temporal clustering of information • E.g. Temporal contiguity effect • Models of Memory Search propose that organizational effects arise because recall process is guided by internal context representation • Temporal Context Model (TCM; Howard & Kahana, 2002) • Context Maintenance & Retrieval Model (CRM; Polyn et al., 2009) • Temporal-contextual cues play an important role in retrieval processes • In the absence of other cues (e.g. semantic), reliance on temporal context cues to probe memory (Unsworth, 2008; Sederberg et al., 2010)

  5. Use of ‘timeline’ techniques • Common ‘sense-making’ tool in investigations • Common in autobiographical memory research • Historical ‘timeline’ and calendar techniques (e.g. EHC) increasingly used technique in social and medical surveys (Belli et al., 2001) • For autobiographical information, timeline formats enhance recall accuracy – particularly when recall task is difficult (Van der Vaart & Glasner, 2007) • Is it possible to adopt a timeline approach for episodic events?

  6. Creating a Timeline Tool • Key Components • Physical Timeline • Report Cards • Action Cards • Person Description Cards • Instructions • Use the Person Descriptions cards to report any details you can remember about the people involved in the event. • Use the Action Cards to report actions / sequence information. • Link any actions or sequence information to the individual or individuals who were involved (i.e. Make clear who did what and when). • Feel free to start anywhere on the timeline and re-arrange Action Cards as necessary to provide an accurate sequence of events. • You are free to use as many Action Cards and Person Description Cards as necessary to recall all the information you remember.

  7. Pilot Results N = 40; Timeline = Significantly more correct details, no differences in accuracy (c.90%)

  8. Research Question: Why does a Timeline Tool elicit more information? • 100 participants (Age M = 28 years, range 18-50 years) • Viewed simulated assault / robbery (1 min 30 seconds) • 5 male perpetrators (all involved; 3 more aggressive) • Female victim • Threatened with iron bar • Laptop stolen and passed between perpetrators • Filler task • Random allocation to reporting condition • Standard Instruction: “Report all the details about the event and the people involved that you can remember. Do not make guesses about things which you cannot remember”.

  9. Design & Instructions • Experimental Conditions • Timeline Tool • Record Cards • Use Action Cards and Person Description Cards • “You can position the cards in any way you want but please make sure that it’s clear which actions link to which perpetrators” • Temporal Context Reinstatement Instructions • CR instructions with emphasis on sequence of events: “Concentrate on the order of events – who did what and when did they do it? Can you link each action to an individual you saw in the order it occurred?” • Free Recall

  10. Using the Timeline Tool

  11. Results F(3,96) = 12.70, p < .001

  12. Results • Accuracy Rates: • No overall differences: overall M = 90%; F(3, 96) < 1, p = .45 • Person, Object, Setting details – no difference in accuracy rate • Action Details; F(3, 96) = 6.45, p < .001

  13. Perpetrator ActionsMean No. Correct Details Reported * = p < .001; no differences in accuracy rate between conditions

  14. Results • Sequencing Errors, F(3,95) = 5.35, p < .01

  15. Summary • More correct information reported in the (interactive) Timeline and Record Card conditions • Enhanced person description • At no cost to accuracy • More perpetrator specific actions correctly reported (for all 5 perpetrators) in the Timeline condition • At no cost to accuracy • Fewer sequence errors in Timeline and Temporal Context Reinstatement Instruction condition

  16. Moving Forward • Role of interactivity in producing a recall account: “It was good because you could write down what you thought of immediately on the cards and then you could go through what you had already written down and re-do it or think ‘wait something happened before that’ and correct or re-arrange it.” (Participant, pilot test of Timeline Tool) • Does this ‘interaction’ increase the likelihood of reconstructive error under particular conditions? • Post event information? • Can this technique enhance: • Recall of Time Details • Particularisation of repeated events • Memory performance following delay (study currently underway)

  17. Practical Application • Overall: Grounding new approaches, techniques and tools on a scientific approach • Promising early results • additional studies underway; refinement of instructions and optimal procedure • Useful for extracting information about multiple suspect incidents • Actions and descriptions • How might the technique be utilised within existing approaches to optimise output?

  18. Thank You! Lorraine.Hope@port.ac.uk

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