This thesis investigates Rapid Serial Visual Presentation (RSVP) procedure as a tool to evaluate sexual interest in child sex offenders. Chapters 1 and 2 evaluate sexual interest in child sex offenders, exploring the attentional blink theories. Chapter 3 examines RSVP in child sex offenders and offenders with no sexual offence history, showing child sex offenders displaying enhanced attentional blink towards images of children. Chapter 4 examined released child sex offenders who did not show the hypothesised attentional blink effect. Chapter 5 looked into RSVP responses of fathers with children under two, and shows an opposite pattern of response to child sex offenders. Chapter 6 showed that RSVP, using male and female images, elicited heightened attentional blink in a normative sample of females, but not the male sample. Chapter 7 examined the RSVP using erotic images of males and females on heterosexual males and females with no significant effect. Chapter 8 tested the reliability and validity of the RSVP in a subsample using the procedure on two separate occasions, showing significant improvement from Session 1 to Session 2. This shows practice effect can influence performance on the RSVP. The main discussion evaluates the results in terms of implications for the utility of the RSVP.