The attribution of authorship to an anonymous text is a common task required of forensic linguists. Yet this seemingly routine task is in fact complex and not without controversy in the forensic linguistic world. There is a strong divide between those who subscribe to descriptive techniques of text analysis and those who adhere to the rigours of statistical validation, usually through computer-assisted analysis of grammatical features. This chapter provides insights into the process of providing an expert report on authorship in a murder trial and demonstrates that in some rare cases, a simple corpus analysis can be applied effectively to a data set. However, the chapter also emphasises that, given the rarity of such cases, the forensic linguistic community is in urgent need of a reliable and valid tool for establishing authorship.