What is the significance of the title ? Is it obvious or hidden ?

lcomb, Kansas; and his wife and two of their children in 1959, and the bloodshed and brutality of their murders is represented by the title. The book looks at the psychological aspects of the crime and examines some of the motivations of the killers to commit such a crime, and so examines as to whether the murder was 'in cold blood' and therefore poses a rhetorical question to the reader, while also provoking the reader to question the motivations and evidence presented to them over the course of the book. You can have a look at the wikipedia page as well, as it gives some more evidence as to why the book was entitled this:

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