The Self-Administered Interview (SAI) tool has been scientifically proven to preserve and protect eyewitness memory by eliciting a detailed recall account at the scene of an incident or soon after.
The SAI was developed to address the serious challenge faced by investigators when an incident occurs for which there are numerous eyewitnesses. Any of these witnesses may hold potentially vital information about the incident and descriptions of the perpetrators i.e. information that will provide both critical leads for the investigation or compelling evidence in a trial. However, investigators do not always have the resources in terms of time, expertise or personnel to conduct detailed interviews with many witnesses shortly after an incident.
Given that eyewitness memory for details of a witnessed incident is under threat in two key ways, the preservation of witness accounts is crucial. In any witnessing situation, memory is prone to decay and this ‘forgetting’ will occur naturally and within hours of the incident. As the delay between witnessing and a formal investigative interview increases, memory decay levels out so while witnesses may still be able to provide a general account, potentially vital details for an investigation may have been irretrievably lost. Another important threat to accurate witness recall is contamination of the original memory by inaccurate information encountered between actually witnessing the event and providing the police with an account of the incident.
To address these challenges, the research team comprising of Dr Lorraine Hope (University of Portsmouth), Dr Fiona Gabbert (University of Abertay) and Professor Ron Fisher (Florida International University) have developed and tested a witness reporting protocol or ‘tool’ that enables investigators to protect witness memory and access detailed witness accounts before that information becomes lost or distorted. Early stage development of the SAI focused on creating a clear set of written instructions and questions that could easily be understood by witnesses while drawing on the core principles of the Cognitive Interview Technique. In early tests of the SAI, mock witnesses (comprising a sample of community volunteers of all ages and background) viewed a simulated event and were required to report as much as they could about what they had seen. Witnesses in who completed the SAI tool reported 42% more correct details than those participants who were simply asked to report what they had seen. In subsequent tests, mock witnesses who had completed the SAI tool shortly after witnessing the event provided almost 30% more correct details when interviewed after a delay than those who had not made an earlier recall attempt. These results suggest that the SAI prevents against memory loss (Gabbert, Hope & Fisher, 2009). Subsequent research has replicated and extended these findings. Specifically, we have found that mock witnesses who complete an SAI after witnessing a simulated crime remember more information following a delay of one month, than do control participants (who have not completed an SAI) after a delay of one week. Furthermore, mock witnesses who complete an SAI are more resistant to the misleading effects of exposure to post-event information and produce more information in a subsequent cognitive interview.
In addition to obvious benefits of enhanced witness recall, the tool also enables investigators to ‘prioritise’ witnesses for follow-up interview meaning that key witnesses are less likely to be overlooked and that resources can be appropriately allocated. In addition, the use of a standardised tool to elicit witness accounts limits a`ny suggestion of ‘improper’ interviewing techniques and reduces any pressure from police or other interviewers which might be inadvertently perceived by witnesses.
In sum, the SAI is an extremely effective investigative tool that protects witness memory, elicits critical information effectively and permits the timely prioritisation of witnesses – particularly in situations where limited resources are available to investigators.