Criminal Career Research in the United Kingdom

The criminal career approach is an exciting new perspective in criminology that has been greatly stimulated by the US National Academy of Sciences Panel on Criminal Career Research (Blumstein et al. 1986), of which I was privileged to be a member. It is not a criminological theory but a framework within which theories can be proposed and tested. This approach defines a 'criminal career' as the longitudinal sequence of offences committed by an individual offender. It is possible to study criminal careers of larger aggregates, such as families, gangs, or communities, but the focus in my paper is on the offending of individuals. Dictionary definitions of the term 'career' specify two different concepts: a course or progress through life, and a way of making a living. The term is used in the first sense here. A 'criminal career' describes the sequence of offences during some part of an individual's lifetime, with no necessary suggestion that offenders use their criminal activity as an important means of earning a living. A criminal career has a beginning (onset), an end (desistance), and a career length in between (duration). Only a certain proportion of the population (prevalence) has a criminal career and commits offences. During their careers, offenders commit offences at a certain rate (frequency) while they are at risk of offending in the community (e.g. not incarcerated or hospitalized). On this definition, a criminal career may contain only one offence or many. For offenders who commit several offences, it is possible to investigate how far they specialize in certain types of offences and how far the seriousness of their offending escalates over time. One of the key distinctions in the criminal career approach is between prevalence and frequency. For example, the age—crime curve shows that the aggregate rate of offending increases to a peak in the teenage years and then decreases. Criminal career researchers investigate whether this peak reflects a peak in the prevalence of offenders or in the frequency of offending (or both). Actually, the existing evidence suggests that this peak reflects mainly variations in prevalence, and that individual offenders commit offences at a fairly constant frequency during their criminal careers (Farrington 1986). The major critics of the criminal career approach, Gottfredson and Hirschi (1986), argue that all criminal career features reflect the single underlying construct of 'criminal propensity'. According to this argument, if criminal propensity is high, the frequency of offending will be high, the age of onset will be early, the age of desistance will be late, and the duration of the career will be long. It is not necessary to distinguish