In NO particular order:
1) Crappy education - Ineffective, lack of discipline in schools, etc.
2) Incarcerated parents.
3) Teenage pregnancy with absent dads.
4) #3 Compounded by absent/incarcerated/immature grandparents.
5) Drug trade. (Not that these kids are hooked, but rather selling.)
And all of the above predisposing factors are increasing, so it's only going to get worse, folks.