Many of these influences are indirect. Especially among male juveniles, the incidence of drug crime is much higher amongst those who do not attend school than it is amongst those who do regularly attend (Office of National Drug Policy 2000). Family structure, in turn, has a huge effect on school attendance. In two parent homes, especially where both biological parents of the juveniles are married and in a healthy relationship, children are much more likely to attend school and to refrain from drug use (U.S. Department of Justice 2001; Office of National Drug Policy 2000). In addition, families with fewer children tend to have fewer issues with criminality altogether and drug use especially than families with more children (Masters & Shear 1998). Though causality has not been fully determined, the correlation between these aspects of family structure and the incidence of drug crimes among juveniles is very strong. It is further borne out by the dramatic rise in suburban drug use that has occurred in recent decades. As divorce and other non-traditional...

Because inner cities have higher rates of poverty and non-traditional family structures than suburban families, there is still a higher incidence of drug criminality in such settings, but this should not cloud the issue of the importance of family structure.
References

Masters, B. & Shear, M. (1998). "As suburbia surges, violence tags along." Accessed 24 April 2009. http://www.washingtonpost.com/wp-srv/local/longterm/library/crime/crime0405a.htm

Office of National Drug Policy. (2000). "Drug related crime." Accessed 24 April 2009. http://www.whitehousedrugpolicy.gov/publications/factsht/crime/index.html

U.S. Department of Justice. (2001). Breaking the juvenile drug-crime cycle. Accessed 24 April 2009. http://www.ncjrs.gov/pdffiles1/nij/186156.pdf