Law Enforcement Agencies gather intelligence in order to prevent criminal activity and "pursue" criminals. In the context of human intelligence collection, intelligence elicitation relies heavily upon the deployment of "appropriate" evidence-based interviewing techniques (a topic rarely covered in the extant research literature). The present research gained unprecedented access to audio recorded telephone interactions (N = 105) between Source Handlers and Covert Human Intelligence Sources (CHIS) from England and Wales. The research explored the mean use of various question types per interaction and across all questions asked in the sample, as well as comparing the intelligence yield for "appropriate" and "inappropriate" questions. Source Handlers were found to utilise vastly more appropriate questions than inappropriate questions, though they rarely used "open-ended" questions. Across the total interactions, "appropriate" questions (by far) were associated with the gathering of much of the total intelligence yield. Implications for practise are discussed.