The story focuses almost entirely on the crime, its aftermath and the investigation. Police Procedural 1. Motivation is usually simple, clues point to the identity of an unknown criminal 3. Criminals are pretty average people and leave a whole host of physical evidence behind them 4. Detectives work on several cases and often must make links 5.
Detectives work as a part of a team with specialists gathering forensic evidence.
Sometimes there is several main characters and Ed McBain changes his emphasis from book to book. Realism in fiction is a bourgeois contrivance. The 'fourth wall' of theatre was not invented until comparatively recently. Marxist authors such as Bertolt Brecht sought to challenge this notion of realism in theatre. Roland Barthes comments on the working class spectacle of professional wrestling which is manifestly unreal yet this does not diminish the experience for a complicit audience.