Interpreting in police settings, as part of public service interpreting, is a field that still lacks empirical and scholarly research which could contribute to shedding light on matters such as service provision and lack of professionalization, crucial aspects that have an influence on the role of the interpreter and which may be at the source of numerous conflicts. Although current legislation in Spain guarantees the right of those detainees who are not proficient in the majority language to be assisted by an interpreter during police proceedings, in practice the situation is much more complex. The intervention of an interpreter is required in many scenarios other than just in detainees’ questioning: transcription-translation of tapped telephone conversations, interpreting for crime victims, translation-data analysis during police investigations, provision of information to people reporting a crime, etc. Given such a wide range of functions, it is clear that interpreters may find themselves in situations that conflict with what is supposed to be their prescribed role. Likewise, despite the provisions in force guaranteeing the presence of an interpreter during questioning, Spanish legislation lags behind social needs, and this creates numerous problems in aspects such as interpreter intervention, the interpreter’s role as cross-cultural and language mediator and the adequate provision of interpreting services. On the basis of evidence acquired through questionnaires and interviews, this paper analyses both service providers’ and interpreters’ perspectives on the role of the interpreter, the conflicts that may arise as a result and the limits to their functions, all within the framework of current interpreting service provision practices in Spanish police settings.