Whilst teenage girls and boys offend at roughly the same rates, the domain of serious offence is predominately that of the boys. What's more, one of the best indicators of whether a boy will offend at 15 is whether he was a victim at 12. If, at 12 or so, a boy has things he holds precious stolen then it is giving him the mandate, later, to reciprocate.

Interestingly, this seems to be a normal male response but not a normal female one. Male offenders and male non-offenders were quite similar in behaviour patterns and attitudes suggesting that it was a product of the circumstances in which they found themselves. Female offenders on the other hand tended to be quite different from other girls in their age group, typically being drug users, gang members, truants, and from a lower class background.

Gang membership generally was a good predictor of offending with the gang providing moral support and encouragement in such activities.

The implications of this excellent research by Economic & Social Research Council in the UK are that programmes targeting offenders and victim support programs need to be rethought within the context that they are targeting the same people. You can read more here.