Everything you need to understand or teach The Fourth Deadly Sin by Lawrence Sanders.
In The Fourth Deadly Sin, Sanders develops three principal themes: psychology, self-image, and police politics.
It is the last one that gets the plot moving. Deputy Commissioner Ivar Thorsen is, as always, embroiled in political intrigues in the New York police department. He has been shepherding his proteges up the departmental ladder to positions of authority, and one of his favorites, Acting Chief of Detectives Michael Ramon Suarez, who is a good administrator but a poor detective, is in trouble because he is having difficulty solving a high-profile murder case; if he fails to solve it by the end of the year, he will not become the permanent Chief of Detectives. To help Suarez, Thorsen turns to former Chief of Detectives Edward X. Delaney, the master of detection, and asks Delaney to run an independent investigation of the murder in order to solve it before year's end, and...