Report highlights include: (1) nearly 1 in 10 persons registered as born in New South Wales (NSW) in 1984 appeared in a NSW court and were convicted of an offense by the age of 21; (2) most of those who appeared in court did so only once and not until after they had turned 18; (3) less than 3 percent of the total cohort or less than 30 percent of those who appeared in court, made their first appearance before the age of 18; (4) males were about 4 times more likely than females to appear in court and also more likely to have appeared at an earlier age; and (5) males were more likely to have appeared multiple times and more likely to have received a prison sentence. Traditionally, in criminology research, there has been a tendency to focus on aggregate level crime rates, meaning the level of crime in a given population over a certain period of time. Building on previous criminal career research, this report presents findings from a study of a cohort of 81,784 individuals born in NSW in 1984 and followed up until the age of 21. Through data obtained from the NSW Registry of Births, Deaths and Marriages, this study sought to answer the following; how many individuals born in 1984 appeared in court for a criminal offense before the age of 21, at what age did they first appear in court, how frequently did they appear in court, what was their first offense, and how many received a prison sentence? Tables, figures, notes, and references