Forensic linguistics is the application of linguistic theory and methods to the forensic context of law, crime investigation, and legal proceedings. In essence, forensic linguistics contains of three main objects of research: studies of legal language, studies of language use in legal settings, and the actual provision of linguistic evidence in police investigations or in trials in court. In this presentation we will discuss linguistic evidence in police investigations and in District courts from a Swedish perspective. There is a plethora of ways that linguists can contribute to all parts of the legal process, from police investigations to interrogations between lawyers and laypersons in District courts and different aspects of written judgements. One example when investigators can engage linguists as experts is author identification. Their expertise can for example provide evidence in cases of threats in various written forms such as letters, e-mails, and posts on social media. Another example is the understanding of how different styles of questioning in police interrogation is performed and what effects it may have for the individual’s right to present their own statements during the police interrogation and for the outcome of the case. Language patterns in legal proceedings and the accessibility of written law are also relevant objects of studies in this field. In this presentation we give an outline of forensic linguistics as a research field, and by giving examples from our own studies, we show how research in forensic linguistic is closely connected to, and relevant for police research in general.