Investigative interviews are a central part of policing. Police interviewers use the information obtained from interviews to develop investigative leads or to make effective decisions. Therefore, it is important that the information is as detailed and accurate as possible. The recognized importance of interviewing has resulted in substantial research efforts being placed into the development of techniques that enhance information provision. One proposal for how these techniques lead to greater information provision is via increased rapport between the interviewer and interviewee. Although numerous interviewing models recommend rapport, the impact of interview style on rapport has rarely been tested directly in interviews with suspects. There has also not been a consideration of how rapport would be affected by repeated exposure to specific individuals and law enforcement in general. In this thesis, I aim to test whether rapport once established can be maintained between multiple interviews and across multiple interviewers. This is a critical gap in our knowledge, as in police interviews it is common practice for suspects to be interviewed more than once and by different interviewers at different times. It is therefore important to know whether previous interactions with the police could affect future interactions in terms of rapport. A second key aim of this thesis is to test if nonverbal mimicry measured via motion capture suits can serve as an objectively rated behavioural proxy of rapport as several studies showed that behavioural mimicry is higher in people with well-established rapport and further, mimicry results in increased rapport. My findings suggest that the interview style impacts on rapport and mimicry. However, I could not find evidence for a link between rapport and disclosed information, or rapport and mimicry.