This is a noir procedural in a far future dystopia where crime families have split a city into four quadrants and basically control everything.
I already mentioned the MC tying this boy into his desire for the son he might never have. The MC also has a deep aversion to the crime families which control the city (his Fixed Attitude). His refusal to have anything to do with the Families caused him to lose his detective shield many years ago, and as a twenty year veteran he's walking a beat in the worst neighborhood of the worst precinct in the city.
The IC (his boss, the precinct commander) is an ill, elderly man, who has worked all his life trying to change the city for the better from inside the corrupt system. He knows his time is short and feels this case is his last chance to make a real difference by getting the crime family which owns his area to allow the police more resources and manpower - or at least to work together to help find this child. He thinks the MC could do a lot of good if he would just Reconsider his aversion to working with the Mob.
The detective on the case is a talented, knowledgeable, but depressed drunk. This case taps into his deep feelings of unworthiness, and he cycles between working on the case and avoiding it (either by being drunk or by working on his other cases instead) because he feels so hopeless. He actually Hinders the case more than anything, and the IC tasks the MC to take over a lot of the work, partially as punishment for one of the MC's Impulsive Responses to another Hinder character.
Those are the main ones working the case. There are others but they have a lesser role.