The Dry by Jane Harper (2017) Flatiron Books

Australian Federal Agent Aaron Falk, a financial forensic detective, goes back to his hometown for the funeral of his best boyhood friend, Luke, who has apparently committed suicide after killing his wife and oldest boy, but not the baby.  The town is in an area going through a drought and everyone is on edge.  Falk was accused, when he was a kid, of killing a friend.  He was fishing at the time, but Luke provided an alibi.  Now everyone in town hates him.  Luke was found in the bed of his pickup along with two unexplained scrapes on the bed.  Finding the real murderer is a twisty tale.