Patterns of criminal activities as they vary by age are very well documented in the literature. Although the majority of offenders cease committing crimes as they age, a small group of offenders remains criminally active into adulthood. The notion of persistence in criminal activity has been the focus of empirical research but has not received much theoretical attention. As such, this chapter describes the theoretical arguments within Moffitt’s development taxonomy; reviews the research on Moffitt’s theory; and analyzes the criticisms levied against Moffitt’s developmental taxonomy. Moffitt’s taxonomy describes two primary types of offenders, short-term adolescent offenders and life-course-persistent offenders, and one type of abstainers who refrain from antisocial and criminal behaviors throughout their life-course. Some assumptions of Moffitt’s taxonomy include the anticipation that males and African-Americans will be more prevalent among both groups of offenders. Studies that have tested Moffitt’s developmental taxonomy are presented and have generally lent support to the key hypotheses of Moffitt’s taxonomy of persistent and adolescent-limited offenders. Next, these two typologies, the persistent versus adolescent-limited offenders, are compared on three outcomes: personality structures, crime types, and persistence in crime into adulthood. Studies that have tested the assertions about gender and race found within Moffitt’s taxonomy are presented and have indicated that females do show less involvement in criminal activities at both levels than males, while the results on the race assertion are less clear but do indicate that levels of risk are higher among non-Whites. The chapter closes with a presentation of future research directions on the continuing assessment of Moffitt’s developmental taxonomy, including the examination of the life events that push adolescent offenders into a life-course-persistent pattern of criminal offending. References