Detecting fake calls to 9-1-1
This study deals with detecting callers who intentionally deceive emergency telephone services. Unlike the majority of citizens using such a service, deceitful callers lie or leave out information that is important to following up on such a call. A previous study showed that deceitful callers behave differently from sincere ones and this study attempts to identify traits in callers’ verbal behaviour that can be most clearly associated with deceit and to determine which of these traits are most readily recognized. The analysis, conducted from an interactionist perspective, was based on a comparison of 45 non-sincere and 40 sincere calls. Eight traits were correlated with caller non-sincerity. Some of these traits are interactional in nature, while others are discursive. Interactional variables proved to be more difficult to codify than discursive ones and this occasionally led to large differences in assessment between analysts. However an analysis model can be constructed on the basis of the four variables for which there was more agreement : clarity of the reason given for the call, pausing before answering a question, sentence structure in which the subject je (I) is followed by the imperfect tense (calls were conducted in French), and, finally, contradictions. An overall correct prediction rate of 82 % for caller sincerity or lack thereof can be reached using these four variables.