Don't miss Steve Sailer's article at VDARE where he makes careful use of L.A. county homicide data to show minority proneness to crime.  

Allow me to add one point to his argument. The state of California has been going after gang-related crime aggressively for a couple decades now. For a given crime, membership in a gang will get you a much longer sentence. Blacks and Hispanics have been disproportionately impacted by this strategy since few gang members are white. If these thousands of gang members were free on L.A. streets, minority crime rates would be substantially higher.