The collection of accurate, detailed, and timely intelligence buttresses critical law enforcement decision-making. However, the quality and quantity of the intelligence gathered relies heavily upon the interviewing techniques used to retrieve it. The perceptions of intelligence practitioners are key to developing an understanding of practices concerning intelligence collection. Yet, to date, no research has been undertaken that explores the United Kingdom's Source Handlers' perceptions of the interviewing processes employed with informants. The present study interviewed 24 Source Handlers from Counter Terrorism Dedicated Source Units in the United Kingdom. Five themes emerged from the interviews, (i) a comparison between interviewing and debriefing; (ii) the PEACE model in intelligence interviews; (iii) the importance of effective communication; (iv) Source Handlers' use of cognitive retrieval techniques; and, (v) Source Handler interview training. The perceived commonalities between interviewing and debriefing provided support for the transferability of investigative interviewing research and practices into the collection of Human Intelligence (HUMINT), reiterating themes (ii), (iii), and (iv). Finally, participants highlighted a need for additional training concerning intelligence gathering techniques, as police officers who are responsible for gathering HUMINT could benefit from further professional development based on investigative interviewing research and professional practices.