Offending specialization has received considerable attention in past research on criminal careers. Relatively little attention has been given to examining the relationships between various sub‐group differences and the extent to which individuals tend toward specialization or versatility in their criminal careers. In the present analysis, we examine hypotheses derived from Moffitt's recent developmental theory that bear directly on offending specialization. Our analysis examines direct relationships between gender, onset age, persistence and offending specialization as well as the interaction of these influences and offending specialization. Our findings reveal results that are both consistent and inconsistent with Moffitt's dual taxonomy of offending behavior.