Purpose In previous laboratory‐based work, the Scharff technique has proved successful for gathering intelligence from human sources. However, little is known about whether the technique can be taught to practitioners, and whether Scharff‐trained practitioners will interview more effectively than colleagues using their conventional approaches and tactics. Method We examined professional handlers from the Norwegian Police (n = 64), all experienced in interacting with informants. Half received training in the Scharff technique, and their performance was compared against handlers receiving no Scharff training and free to use the approaches they saw fit. All handlers received the same case file describing a source holding information about a future terrorist attack and were given the same interview objectives. Police trainees (n = 64) took on the role of semicooperative sources and were given incomplete information about the attack. Results The trained handlers adhered to the Scharff training as they (1) aimed to establish the illusion of ‘knowing‐it‐all’, (2) posed claims to collect information, and (3) asked few (if any) explicit questions. In contrast, the untrained handlers tried to evoke the sources’ motivation to reveal information and asked a high number of explicit questions. Scharff‐trained handlers were perceived as less eager to gather information, but collected comparatively more new information. Conclusions The Scharff‐trained interviewers utilized more specific elicitation tactics (e.g., posing claims) and fewer general interview strategies (e.g., evoking motivation), and they collected comparatively more new information. This captures the essence of the Scharff technique: It is subtle, yet effective.