The age-crime profile is one of the most established and prominent emp
irical regularities in social science. This paper formulates an econom
ic dynamic model of illegal behavior to explain the age-crime profile.
The model offers a new interpretation of the age-crime profile that i
s entirely different from the prevailing one in the literature. The im
plications of the model are testable and are consistent with the empir
ical evidence examined in the paper. The analysis shows that intertemp
oral criminal decisions can be modeled as a dynamic consumption-invest
ment problem.