Previous research has established a strong relation between an early onset of delinquent behaviour and future persistent offending [1–5]. Childhood offenders, i.e. children who display delinquent behaviour prior to the age of twelve1, are two to three times more likely to become serious and persistent offenders than those with a later onset [4, 6, 7]. In addition, these children have an increased risk of developing mental health, social and educational problems during their lives [7–9]. Most research on childhood offending is based on general population studies in which childhood offenders have been analyzed as a homogeneous group [9, 10]. However, not all children have a similar risk of starting offending in childhood and not all childhood offenders are as likely to re-offend. According to self-reports approximately 15% of all children display a stable pattern of antisocial and offending behaviour during childhood, of whom only half will persist in serious offending during adolescence. Children living in disadvantaged neighbourhoods are known to have an elevated risk of starting delinquent behaviour as compared to children from more affluent neighbourhoods [7, 11]. Among children from disadvantaged neighbourhoods, children from ethnic minorities are at an even higher risk of becoming childhood offenders when compared to Dutch children from comparable neighbourhoods . Despite this risk most children from ethnic minorities living in disadvantaged neighbourhoods do not become childhood offenders. Moreover, those who do will not necessarily persist in delinquent behaviour. In order to appropriately target interventions and address the relevant risk factors, it is essential to gain insight into which risk factors are associated with offending and re-offending. Therefore, this study focuses on risk factors that may distinguish non-offenders from one-time offenders and re-offenders in a high-risk group of ethnic minority boys from disadvantaged neighbourhoods in the Netherlands.
Officially registered offending is in particular a strong predictor for a persistent pattern of delinquency . Nevertheless, most knowledge of childhood offenders is currently based on self-report studies in the general population. Risk factors found for childhood offending are for instance: individual risk factors like mental health problems and problems at school, family risk factors like large families, financial problems, parental delinquency and other parenting problems, and environmental risk factors like living in a disadvantaged neighbourhood and affiliation with delinquent peers. Studies focusing on risk factors of officially registered childhood offenders remain scarce and studies examining the risk factors of registered re-offending childhood offenders are even scarcer [13–17]. Furthermore, studies are inconclusive regarding characteristics differentiating one-time offenders from re-offenders. For instance, whilst some found that persisters are more likely to come from dysfunctional families living in disadvantaged neighbourhoods compared to one-time offenders [e.g.,[14, 16]], others found no differences in individual, family or neighbourhood characteristics between one-time and re-offending children [9, 13]. Additionally, some have stressed the predictive value of violent offences, whereas others found that less serious offences are equally predictive of a persistent pattern of offending [13, 18, 19]. Nevertheless, most researchers agree on a high probability of an early police encounter for boys from ethnic minorities from disadvantaged neighbourhoods [10, 12, 20, 21].
However, ethnicity alone is uninformative about which characteristics put these children at an increased risk, as it is not known whether risk factors found for offending in general populations also hold for childhood offenders from ethnic minorities. More importantly, it is unclear which risk factors differentiate one-time offenders from re-offenders among childhood offenders from ethnic minorities. Van Domburgh et al.  found that among non-Western children from disadvantaged neighbourhoods, a combination of individual, peer and parental problems differentiated the level of childhood offending. However, these results can not be generalized since this study included all non-Western children, while these children in fact comprise a heterogeneous group.
Certain minorities tend to be over-represented in the national justice systems and in institutions for delinquent youth. Like Algerians in France, Turks in Germany and West-Indians in England, Moroccans are over-represented in police and justice systems in the Netherlands [22–24]. Moroccan immigrants belong to one of the largest migrant groups in the Netherlands. Currently, two percent of the Dutch population is of Moroccan origin. Migration began in the 1960s when Moroccan man were recruited for working in the Dutch labour market. Nowadays, about 40% of the Moroccan immigrants are born in the Netherlands. Dutch police records show that Moroccan juveniles, in comparison to both native Dutch and other ethnic minority groups, are over-represented in the population of juvenile delinquents and in justice youth care [25–27]. There are many reasons for this over-representation, including racial discrimination, selective arrest and intake in the justice system and a high exposure to risk factors associated with delinquency . For instance, Moroccans communities in the Netherlands face social-economic disadvantaged like poverty, unemployment and poor housing conditions . Furthermore, certain individual risk factors, like behavioural problems, may exert a relatively strong influence on childhood offenders with a Moroccan background (further called Dutch-Moroccans) as these problems tend to remain untreated among Dutch-Moroccan youth and may escalate into delinquent behaviour later [29–31]. As a result, mental health care for Dutch-Moroccan youth is often characterized by a juridical framework . Moreover, Dutch-Moroccan children have language problems from the beginning of elementary school onwards, which is strongly associated with educational problems and dropping out later on . In addition to these somewhat general risk factors, specific risks among ethnic minorities like acculturation problems have been related to delinquency [34–36]. Acculturation is the way in which people relate to their ethnic and host culture. It is assumed that a strong orientation to both ethnic and host cultures gives the best quality of life for children and therefore leads to the lowest risk of delinquent behaviour . In contrast, using Merton's strain theory  migrants who are strongly orientated towards the host society are at an increased risk of delinquent behaviour because of discrepancies between pursued goals and possibilities to achieve those goals. In addition, instead of integrating into the host's middle class, migrants more often unintentional integrate into the host's 'underclass' where delinquency is more prevalent. This may also increase delinquency in those integrated migrants .
In summary, there are many risk factors associated with offending present in Dutch-Moroccans in the Netherlands. However, it is unclear which risk factors differentiate between non-offending, one-time offending and re-offending in a high-risk group of Dutch-Moroccan boys. Insight into these risk factors is of great importance in order to tailor interventions while maximizing efficiency. Therefore the aim of this study was to investigate which individual, family and acculturation risk factors differentiate non-delinquent, one-time offending and re-offending Dutch-Moroccan boys. In addition, offence characteristics between one-time offenders and re-offenders are compared.
Given the high-risk profile of Dutch-Moroccan boys in the Netherlands, we expected most participants in our study to have individual and family characteristics that are generally acknowledged as risk factors for offending. Overall, we expected these risk factors to be most prevalent in re-offenders. Due to their low attendance at voluntary mental health care facilities and the strong association between behavioural problems and delinquent behaviour, we expected re-offenders to have more behavioural problems and to have received more mental health care within the juridical framework. In addition, we expected offenders and re-offenders to be more oriented towards Dutch society compared to the controls.
This present study is to our knowledge the first study that focuses on a high-risk subgroup of childhood one-time offenders and re-offenders from a single ethnic minority group. Moreover, instead of self-reported delinquency, we used police registration to define one-time offenders and re-offenders and compared these boys with a matched group of non-delinquent Dutch-Moroccan boys. Finally, whereas most studies rely on either self-reports or police registrations, this study made use of multiple sources: official police registrations, child and parent reports and information from the Child Welfare Agency.