Tim Grant is the UK's only Professor of Forensic Linguistics, at Aston University, providing academic research and expert investigative assistance to UK and overseas police forces as well as providing evidence for both prosecution and defence and in civil cases. He is a former President of the International Association of Forensic Linguists.

1. Introduction; 2. Data and methods; 3. Experimental results; 4. Training identity assumption; 5. Resources and constraints in abuse identity performance; 6. Contexts for linguistic investigative advice; 7. Implications and future directions.

"This book provides an account of our theoretical approach to identity and its relationship with linguistic performance, particularly within the context of online criminal interactions and communities. We report on findings from a project investigating the assumption of identities online, drawing on Instant Messaging (IM) data from a variety of contexts, both 'real life' and experimental, in order to expound the implications of our approach for the training and professional practice of online undercover investigators"--