Age-specific arrest rates for the United States at the crime peak of the late 1980s and early 90s are compared to those for 2010. Three key features are explored; (1) The disproportionate decline in adolescent offending; (2) The decline in this age-effect up to age 40; (3) Offenders aged in their 40s who in 2010 offended at higher rates than offenders of that age at crime’s peak. The first two are interpreted as consistent with the debut crime hypothesis: crime fell because reduced crime opportunities made adolescent crime, and hence criminal career onset and continuance, more difficult. We interpret the third as a legacy of increased onset and habitual criminality fostered by exploitation of the plentiful crime opportunities of the 1970s a...