The study follows a cohort of 15,117 individuals from the age 15 to 30. For both males and females, the age-based transition probabilities are studied; the transitions for females conform to a first-order Markov chain. The original matrices can be seen as estimates from a single "parent matrix." This was not found to be the case for males. The study also looks at the discriminatory power of prior criminality for later transition probabilities, and it emphasizes the difference between the statement that a given percentage will relapse in crime and the ability to make real prediction. 12 tables, 5 matrices, 2 notes, 17 references. (Author abstract modified)