The lengthy official records of these youths permit a reliable, detailed analysis of offense patterns through the use of up to 42 successive arrests. The data also permit separate analyses of offense specialization for frequent offenders (defined here as those with 10 or more arrests), as well as comparisons of offending patterns of racial/ethnic groups and groups from four regions. The data include both juvenile and adult arrests and span at least one incarceration. The subjects of the analysis are a random sample of 1,998 male youths released from the California Youth Authority between July 1, 1981, and June 30, 1982. The findings are in some ways similar to and in other ways different from those reported by other researchers. Findings show adjacent transition matrices are apparently constant; the same cannot be said for nonadjacent matrices. Researchers reject the first-order Markov hypothesis and find support for specialization in the statistical significance of the forward specialization coefficients. Results also suggest that, in addition to transitions to the same type of offense, an oscillating pattern of offending is common for the subjects. The study also compares the transition matrices of three racial/ethnic and four regional groups. Results show differences in the patterns of offending by the racial/ethnic groups in the sample and similar offense-transition behavior in three of the four regions that differs significantly from that of the fourth region. 11 tables and 18 references