This timely volume by leading researchers in Life Course Criminology reports new findings from The Cambridge Study in Delinquent Development, a prospective longitudinal survey of 411 South London males first studied at age 8 in 1961. The main aims of the study are to advance knowledge about conviction careers up to age 56. Forty-two percent of the males were convicted, with an average ten-year conviction career. Only seven percent of the males accounted for half of all convictions. Based on these results, risk assessment instruments could be developed and risk-focused prevention could be implemented in early childhood, including parent training, pre-school intellectual enrichment programs and home visiting programs, in order to prevent chronic styles of offending from being initiated. This work will be of interest to researchers in criminology and criminal justice, particularly with an interest in life course criminology and crime prevention, while also being of use as a research framework for other studies.