Research in the field of sexual aggression often assumes escalation in the criminal careers of sexual offenders. Sexual offenders are thought to begin their criminal careers with non-contact sexual offenses or non-sexual offenses and then escalate to more serious crimes, specifically sexual violence. The commission of one crime in particular—burglary—has been found to be a predictor of future violence in sexual offenders. The present study investigated the nature and extent of escalation in the criminal histories of 161 sex offenders who committed at least two burglaries. Six types of escalations were considered: type of burglary, occupancy, violence, weapon, frequency, and the victim–offender relationship. Escalators and non-escalators were compared, differences between the groups were reviewed, and the cumulative effect of various forms of escalation was analyzed. Results indicated that escalators and non-escalators could be differentiated on a number of important dimensions that might assist in the earlier detection of subsequently more dangerous offenders.