Findings

Delinquency in the study population and the national population

During the period from their 8^th to their 18^th birthdays, children and youth born in 1987 were responsible for 47 recorded offences per 100 population, or approximately one offence for every two persons in the birth cohort, in the parts of Canada included in the study. [Full text]

The age-crime curve

The amount of recorded crime committed by members of the study population at different ages follows the familiar "age-crime curve". [Full text]

Age and the prevalence of delinquency

Participation in police-reported crime is very low at the younger ages: only 0.033%, or one in every 3,000 5 year olds, were recorded by police as being implicated in a crime. [Full text]

Sex and the age-specific prevalence of delinquency

As is found by all sex- and gender-specific research on crime, the prevalence of male delinquency is much higher than that of females. [Full text]

Age-specific prevalence of different types of offenders

Consistent with other research, the level of property crime is highest at all ages included in this study. [Full text]

Cumulative and "lifetime" prevalence of delinquency

While age-specific prevalence statistics give an idea of the development with age of delinquent and criminal activity in the population, they do not show the cumulative effect of this development. [Full text]

Sex and the cumulative prevalence of delinquency

Male prevalence is higher at all ages, and it has not levelled off by the age of 17, where it reaches a level of 25%, or one in 4 male cohort members.  [Full text]

Cumulative prevalence of different types of offenders

By 17 years of age, 6.2% of the 1987 cohort had been apprehended in connection with an offence against the person; 12.2% for a property offence; and 6.2% for another offence. [Full text]

Age and the rate of offending

Participation in, or the prevalence of, delinquency, was found to increase with age to a peak of 5.8% at 16 years. [Full text]

The onset of the delinquent career

The age of onset of a delinquent or criminal career refers, in principle, to the age at which the person first commits a delinquent or criminal act. [Full text]

Sex and the age of onset

Defining early onset as occurring before the 12^th birthday, 2.6% of male cohort members, or 13% of recorded male offenders were early onset; the figures for girls are 0.7% of cohort members and 7% of recorded offenders. [Full text]

Onset and the type of offence

The rate of onset of each type of offence is rather different for girls than for boys. [Full text]

The duration of the delinquent career

The duration of a delinquent or criminal career is the length of time between the first and last incidents in the career. The date of the last incident – the "termination" of the career, or "desistance" from crime – is difficult or impossible to determine without tracking the subject to his or her death. [Full text]

The duration of the career and the age of onset

It has repeatedly been found that an early age of onset is associated with a longer (and more serious) criminal career. However, this association has been found to be weaker or nonexistent when only the delinquent career is examined (Kazemian & Farrington, 2006). [Full text]

The amount of delinquent activity

The number of recorded criminal incidents in a delinquent career is an indicator of the overall extent of the offender's delinquent activity. [Full text]

Delinquent activity and age of onset

One of the common findings of criminal careers research is that children who begin early to engage in antisocial behaviour and delinquency are more likely to become chronic and serious offenders. [Full text]

Specialization and versatility in offending

Criminological research on representative samples of offenders, rather than case histories of "professional" criminals, has consistently found little or no evidence of specialization in specific types of crime, but much evidence of specialization in broad categories of crime (Piquero et al. 2007: 75). [Full text]

Changes in the seriousness of offending over the delinquent career

The research evidence on changes in the seriousness of crime over the course of the delinquent or criminal career is mixed. [Full text]

Summary and conclusions

This report has examined the involvement in police-reported crime during 1995 to 2005 of children and youth born in 1987 and 1990, in the parts of Canada covered by the Incident-Based Uniform Crime Reporting Survey. [Full text]