Considerable emphasis is placed on the importance of building rapport when interviewing witnesses and suspects. Despite the abundant literature on the working alliance in therapeutic settings, however, few studies have addressed the topic of 'rapport' in investigative interviewing. Conceptual analysis revealed a number of similarities between the two constructs. This finding suggests the possible benefits of using the theoretical therapeutic construct and operationalisation of the working alliance in order to gain insight into the dynamics of investigative interviewing in a police context. The present study examines the perceptions of witnesses and suspects regarding the working alliance in actual interviews. It also considers their perceptions of interviewing style, which is another key element in investigative interviewing. In addition, the study investigates the relationship between the working alliance and the interview style. Self-report questionnaires completed by investigators and interviewees showed significant differences between investigators and suspects and between witnesses and suspects with regard to perceptions of interview style and the working alliance during interviews. The results showed perceived interview style to be a predictor of the working alliance.