The aim of investigative interviews is to gather comprehensive and reliable information from suspects, offenders, victims and witnesses through questioning. Research on questioning during police interviews has mainly explored question types and question approaches when interviewing adults and children. This paper is concerned with so far unexplored aspects of police interviewing, that is the employment of mitigating and aggravating linguistic devices in questions and statements and their pragmatic effects. The corpus consists of six police interviews with suspects of crime. Mitigation and aggravation strategies were extracted and a total of eighty-two instances were found, analysed and classified into a categorisation taxonomy which was designed to ascertain the types and functions of mitigation and aggravation devices. The findings reveal that more mitigation than aggravation strategies were used in police questioning and statements during the interviews. Mitigation was found to be used not only as a device for alleviating or attenuating, but also as a strategy to build rapport between suspects and police officers.