detective / police dramas are one of the most overused genres. But, most investigations in real life are not page-turning mysteries that keep the detective guessing until and explosive discovery that links together seemingly innocuous threads. But rather, a guided process, where the detective already has an idea of the perpetrator(s) involved, and simply needs to collect enough supplementary evidence to ensure a strong case.
This would make for a rather uninteresting novel / show on its own. The genre is so swarmed by tropes & expectations, that falling dead flat, subverting this, could make for an entertaining story, if sufficiently enveloped in a side-plot (that, contrary to the tropes in mystery novels, is actually the main story)
-generic explosive opening, detective immediately suspects the shifty-eyed family member. Cryptic comments from one of the witnesses that suggest it could be someone else. Lots of red herrings that, despite what the detective thinks, the reader assumes they can read between the lines, and it was actually another perpetrator
-anti-climatic resolution of the crime. No midnight Eureka that the suspect's middle name was used on court documents in a shell company to move money around, unintentionally linking them to the crime. In an afterthought to the novel, he (checks security tapes / gathers statements from witnesses / gets the suspect to break down and confesses, after an innocuous interrogation session). The reader is left disappointed & confused, but the plot continues, as it isn't a detective novel in the end.
Not sure what the larger story is at this time. Likely branches out into the lives of one of the characters the detective meets while on the investigation.
Love story? Starred eyed new-comer thrust into a world of unique compelling characters? Slow-rolling character study that's lack of plot is the point, and is driven by the strength of its dialogs & realism?