Don’t expect either a Dashiell Hammett rerun or anything like the movie when you decide to read Elroy’s tome.
The stream of consciousness is a bit hard to follow (not knowing whose stream it is until the narrative identifies the POV) but the language is exactly right for the story. The dialog is cop-speak and is also right for the story that takes place in 1953-58 with a returning explanatory sequence in the 1930s that is unclear until the end of the novel.
If you’ve seen the movie be prepared to understand that it was a highly sanitized version of the story. Elroy revels in the most degrading, disgusting and violent aspects of the lowlife he uses for the story’s setting. You’ll also note that the characters shift from the film to something more in tune with everybody having flaws as well as golden moments.
Elroy uses very short chapters to move the story along and it does move along although his plot is so complicated that it takes all of the 495 pages (paperback) to bring it to a conclusion.