To start:
This is a cop show. There's no pretending otherwise. And, as all other cop shows go, it is inherently pro-cops. In fact, a huge part of the plot revolves around what it means to be a Black cop and what it means to be a Black non-cop. It also isn't afraid to face you directly with cop violence, even if they do just kind of let it go because a character was grieving. (Which is not a justified excuse, but feels in-line with how real-life police departments do excuse away any violence on their parts) I won't speak any further on that, because it's not my place. But it does feel like the show goes into this knowing that it's a heavy subject matter.
But the running theme of the show is grief, and all the messy, complicated, and even weird things that come from it. The whole show is about the family you're born to, and the family you make. It's rare to see such a complex family dynamic shown in TV where it's not all or nothing, and no one is inherently "bad" or "good". They're just... people. And they love each other in those complex ways that families do. Even the twist ending reflects a tangled family dynamic, where there is no black and white.
Overall, it's a decent mystery and cop show. But what really makes it good is the thoughtful writing of family dynamics and all the, sometimes flawed, social systems that shape them.