ABSTRACT
In an earlier article in this journal, Barnett, Blumstein, and Farrington (1987) formulated a model that described the criminal careers of the multiple offenders in a cohort of London males that had been studied from their 10th to 25th birthdays. That model involved two subpopulations of offenders (denoted as “frequents” and “occasionals”), each characterized by a constant annual conviction rate (μ) and a constant probability (p) of terminating the career following a conviction. This article describes the results of a prospective and predictive test of the model using new data collected on the same offenders from their 25th to 30th birthdays. The original model accurately predicted the number of recidivists, the degree of recidivism risk, the total number of recidivist convictions, and the time intervals between recidivist convictions. However, the predictions for the frequents suffered some distortions introduced by a few “intermittent” offenders who seemed to have terminated their careers, but who re-initiated offending during the test period after a long gap.
