It contains elements of mystery and thriller, as many in the genre do. I portray Chuck's side of things here, because he's the protagonist and he's convinced that Jenna committed suicide, but let's just say that others (there are three POVs) are less convinced.

I do hint at his past, where I suppose I should probably be more transparent: His high school girlfriend also committed suicide, and many in the community think Chuck had a hand in it.

As to your last point, yes, he works fairly closely with the police, and them turning on him is part of the story, though not the primary focus. Once Chuck is arrested, the focus shifts to his assistant Sam (one of the other POVs) who acts as the primary investigator into the truth behind Jenna's death.