Mapping Details to Elicit Information and Cues to Deceit: The Effects of Map Richness

Background: Investigators often use maps in forensic interviews to verify a route that was taken by a suspect to obtain additional information, and to assess credibility. Method: We examined the effects of the level of map richness on the elicitation of information and cues to deceit. A total of 112 participants completed a mock secret mission and were asked to tell the truth (to a friendly agent) or to lie (to a hostile agent) about it in an interview. In phase 1 of the interview, all participants provided a verbal free recall of the mission. In phase 2, half of the participants were given a detailed map that included all street names and landmarks of the city where they completed the mission (zoomed in to 80%), and the other half were given a less detailed map that included the names of only major streets and landmarks (zoomed in to 60%). All participants were asked to verbally describe the mission and the route taken while sketching on the map. Results: Compared to lie tellers, truth tellers provided more location, action, temporal, and object details and complications in phase 1, and new person, location, action, and object details and complications in phase 2. Map richness did not have an effect on the amount of information elicited and had an equal effect on truth tellers and lie tellers. Conclusions: This initial experiment in this research area suggests that investigators do not have to worry about the exact level of map detailedness when introducing maps in interviews.