Detecting informant deception is a key concern for law enforcement officers, with implications for resource-management, operational decision-making, and protecting officers from risk of harm. However, the situational dilemma of a police informant, otherwise known as a Covert Human Intelligence Source (CHIS), is unique. Informants are tasked to obtain information about the transgressive actions or intentions of their associates, knowing they will later disclose this information to a handler. Thus, techniques for detecting deception in other forensic scenarios may not be transferrable to an informant interview. Utilising truthful and deceptive transcripts from a unique mock-informant role play paradigm, Smallest Space Analysis was used to map the co-occurrence of content themes. Results found that deceptive content frequently co-occurred with emotive and low-potency content themes. This provides support for the future analysis of verbal content when seeking to detect informant deception.