The method separates the influences of criminal career termination from the frequency of offending in followup arrest information for a sample of offenders. The method also incorporates an accelerated failure time model to detect the influence of offender attributes on the termination rate. The method was employed in an analysis of 20,117 adult males arrested for a serious offense in Detroit between January 1974 and December 1977. The estimated overall average termination rate from serious offending was determined to be 14 percent per year, which corresponds to an average career length of 7 years. Higher termination rates and shorter offending careers are exhibited by white versus black offenders and by those arrested outside rather than inside the central city area. Additionally, among offenders arrested outside the city area, a higher termination rate is estimated for older versus younger offenders and for black offenders with prior arrests compared to first-time offenders. Mathematical parameters of the method used to assess the termination rate of adult criminal careers are described. 22 references, 5 tables, and 4 figures