Interesting parallels to be had between D'Angelo and Ziggy, doncha think - sons ill-fitting the family business, etc?
Also interesting parallel with these two and Prez: another one who doesn't really fit the traditional family business: he finds that he is good at the admin and problem solving part of the wire tap, but that he isn't as good at the traditional police work out on the streets.
Of course, Prez is the only one who escapes the family business and finds something else that he is good at. The other two, trapped by poverty (of choices and aspirations, as well as the regular kind) aren't so lucky).