I want to mention though a book I received a few months ago from the nice people at Bloomsbury, because this book illustrates a very interesting technique that's rarely seen in detective stories.
The book's The Third Rail by Michael Harvey, and the technique is omniscient third person. The Third Rail is a hardboiled PI detective tale starring an Irish ex-cop in Chicago. All relatively standard stuff, you might think.
I was chugging along happily, rather liking the book's voice, watching the bodies pile up at a rate that would make even Nicolaos wince, when about halfway in, something unusual happened. A bad guy decided to kill a whole lot of people (I'm tiptoeing around spoilers here...). As each victim died, or was seriously injured, the book stopped to tell you what the victim's life would have been like if he or she hadn't been hurt.
Here's an example:
His fourth [shot] punched through the chest and burst the heart of forty-seven-year old Mitchell Case, a second-rate accountant who would never find out about the first-rate affair his wife was having, not to mention the malignant tumor percolating inside his skull. Case's Corolla was traveling at twenty-eight miles an hour when he was struck. The car hit the divider, jumped it, and plowed into a van heading north. That driver, eighteen-year-old Malcolm Anderson, would never meet his daughter, Janine, because she'd never be born.
And so forth. By the time this scene finished, it was a busy day at the office for the morgue attendants.
Now The Third Rail is written in close third person, which is the most common point of view. But this scene has flipped into omniscient third, deliberately and to great effect.
Point of view is how the book tells its tale via a narrator. (I'll call it POV from now on.)
First person POV is an "I" book. I pulled out a knife. I waved it around, because I thought it would scare her. She laughed at me. The Athenian Mysteries are written in first person from the point of view of Nicolaos. In a first person book you always see inside the head of the narrator.
Close third person is a "he/she" book, in which we see inside the head of the narrator. Fred pulled out a gun. Jane thought he looked ridiculous. She laughed at him.
Distant third person is a "he/she" book in which we follow a particular character but don't see inside his head.
You surely know that in third person, it's easy to switch from one narrator to another. In one scene we might be viewing the action from Jane's point of view, in the next scene we might see through Fred's eyes. Changing narrator is a normal POV switch.
But here we have something else again. This book does a POV switch into omniscient third. The new narrator is a godlike being -- not one of the characters -- a godlike being who looks down from above, and tells us what's going on. As you can see from the excerpt, omniscient narrators not only know everything, but they can also see the future, and the past, and look into alternate world lines.
Omniscient third is very rarely seen in detective fiction because, since the omniscient narrator sees all and knows all, including who the killer is right from the start, it's going to be a very short story. You could, in theory, have an omniscient narrator who deliberately hides his knowledge from the reader, but that would mean the omniscient narrator is also an unreliable witness. At this point the author feels a migraine coming on and has to take some headache pills and have a good lie down.
So all in all I thought Harvey did a great job of switching into omniscience, on that one big set piece scene, and then switching out of it. By limiting his omniscience, so to speak, he managed to get the benefit without the usual drawbacks.