In investigating crime, police rely upon information obtained from witness interviews. Witnesses and police frequently come to an interview with different expectations based upon their respective, sometimes competing, needs. Witnesses are often focused upon procedural justice considerations with some uncertainty about the interview process. Police are often operationally focused on the evidence they require and may need information quickly to apprehend an offender. The manner in which witness interviews are conducted can have a significant bearing upon the quality and quantity of information obtained and its usefulness to the criminal justice system. In addition, should the procedural justice expectations of a witness go unmet, this can have significant implications upon perceptions of police legitimacy and ultimately cooperation with the police. This paper discusses witness interviews from the perspective of the protagonists' expectations and explores how police interview behaviour might impact upon public perceptions of and cooperation with police.