A critical line of research pertaining to the criminal careers of sexual offenders has been concerned with the continuity of sexual offending behavior over the life course. If adult sexual offenders were not typically juvenile sexual offenders, then two particularly important questions are: (1) What do their antisocial developmental backgrounds look like in youth? (2) What characterizes the developmental trajectories of these men leading to sexual offending in adulthood? This chapter examines the characteristics of antisocial trajectories in youth of adult sexual offenders of women and adult sexual offenders of children. It explores the relationship between antisocial trajectories in youth and criminal involvement in adulthood. It then examines the relative contribution of antisocial trajectories in youth to the activation of adult criminal careers to investigate the impact of different patterns of youth delinquency on the continuity of offending into adulthood among sexual offenders of children and sexual offenders of women.