Sexual abuse research suggests that sexual offending is usually preceded by nonsexual offending, but little else is known or understood about the specific kinds of nonsexual crimes or patterns of crime that occur before serious sexual offending. The present study examined the official criminal histories of 751 men convicted of sexual offenses and referred to the Massachusetts Treatment Center for civil commitment. This relatively serious and chronic sample was arranged and compared with the type of their first officially recorded offense. Those whose first official charge was for a sexual offense ("sexual onset") were compared with nonsexual "violent onset" and "property onset" offenders. Important differences were detected between groups. Those with a property onset experienced more criminological risk factors and reflected the characteristics typical of chronic offenders. These results indicate that a more dedicated understanding of the beginning of one’s criminal career is a beneficial direction for future study.