This thesis explores the strategies used by online sexual groomers and the role of offence motivation. Chapter 1 introduces the phenomenon, highlighting the importance of understanding the process of grooming in order to effectively safeguard young people in an ever-expanding online world. Chapter 2 explores the psychometric properties and utility of the Multiphasic Sex Inventory to assess Internet offenders. Following a discussion of the strengths and weaknesses of online sexual grooming research methodology, a systematic re-view of literature investigating grooming narratives is presented in Chapter 3. The review identifies that in-depth qualitative findings require replication with larger statistically significant sample sizes and different grooming offence motives require further attention. Chapter 4 presents a research study analysing narrative themes in the grooming transcripts of 75 contact-driven and 75 fantasy-driven offenders. Six narrative themes are identified which complement the Self-Regulation Model of online sexual grooming (Elliott, 2015). The narrative theme of Sexual Desensitisation is found to contribute to a predictive model for offence motive. The thesis and its utility is discussed in Chapter 5. This thesis directly supports and justifies the introduction of a new sexual communications law in April 2017 criminalising non-contact online grooming interactions.