This Element explores the analysis of deception in written texts from a forensic linguistic perspective. It provides an overview of the evolution of deception research and philosophy, from its earliest conceptualisation as a sin against God, to cue leakage theories and pseudoscientific beliefs built on medieval concepts of deceptive behaviour, to current psychology and linguistic based approaches to identifying lying. This requires an appreciation of where linguistic analysis fits into the eight decades plus of deception research, which is addressed here: the relationships between deceptive intention and communication; between emotional states and the linguistic features claimed to represent them; and between language and linguistic analysis. This Element is written for the non-linguist professional, especially those engaged in investigative and inquisitorial contexts, to provide them with some knowledge to assess the strengths and limitations of approaches to analysing lying and deception as produced in written texts.