The Blunderer by Patricia Highsmith

The novel revolves around a man named Walter Stackhouse, whose life spirals out of control after he becomes obsessed with the murder of a woman that bears similarities to his own marital troubles. As Walter's fascination with the crime deepens, he finds himself entangled in a web of suspicion and deceit, leading to a series of misunderstandings and dangerous encounters. The story explores themes of guilt, obsession, and the thin line between innocence and culpability, as Walter's actions inadvertently draw the attention of a relentless detective and put his own life at risk.