Edgar Allan Poe is credited with being father of the detective mystery, but Arthur Conan Doyle elaborated on it with his Sherlock Holmes stories and novels. The typical English murder mystery had a small setting and limited number of characters who could be considered suspects. A good example is Agatha Christie's And Then There Were None, in which all the suspects were confined to an island and the plot focused on discovering which one was guilty.
This kind of tight plot did not suit modern America because it is so big, so densely populated, and because so many people are newcomers, drifters, strangers, and eccentrics. Dashiell Hammett and Raymond Chandler both contributed to fashioning an American-style murder mystery which covered a broader canvas. Hammett's The Maltese Falcon, set in San Francisco, was still limited to a narrow setting because of the compact nature of the city. Sam Spade doesn't even drive a car. He rides a streetcar once or twice and takes a taxi on a couple of occasions. The number of possible suspects is limited because only a few know about the black bird.
Chancler writes about Los Angeles, an enormous city sprawling in every direction and dependent on automobiles. In the opening scenes he introduces two automobiles along with several important characters, including General Sternwood and the old man's two daughters.
There were French doors at the back of the hall, beyond them a wide sweep of emerald grass to a white garage, in front of which a slim dark young chauffeur in shiny black leggings was dusting a maroon Packard convertible.
The chauffeur is Owen Taylor. He will kill Arthur Gynnn Geiger that night. The Packard convertible belongs to Carmen Sternwood, and she will use it to drive to Geiger's bungalow in the Hollywood Hills. She would have no other way of getting there. When Marlowe follows the butler out to the greenhouse, he notices that
The boyish-looking chauffeur had a big black and chromium secdan out now and was dusting that.
This big Buick will end up in the ocean with Owen Taylor's body inside. Late in the story Marlowe is being tailed by a four-door Plymouth driven by Harry Jones. Chandler's plots are notoriously hard to follow, but they still feature a detective who is trying to solve a problem eventually involving several murders. First it is Geiger who gets shot. Then Owen Taylor dies in the Buick, and even Chandler couldn't explain whether he was murdered or committed suicide. Then Harry Jones is killed by Lash Canino with whisky containing cyanide. Later Marlowe kills Lash Canino outside Art Huck's garage.
But the real mystery is what happened to Rusty Regan. The General doesn't tell Marlowe he wants him to find out where Rusty went, but Marlowe understands that this is the real problem, and he does some extracurricular investigation. Characteristically of the murder mystery genre, the story has a surprise ending. Rusty was murdered, and the perpetrator was none other than Carmen Sternwood.
The story covers a vast area and depends on cars. There are a number of kinky people involved because, after all, this is L.A. Geiger and his good friend Carol Lundgren are gay. Geiger rents pornographic books and uses exotic drugs. Chandler showed how the traditional English murder could morph into plots more suited to the modern world, in which anybody could be the victim and anybody could be the killer. Chandler also introduced American vernicular hardboiled poetry to detective fiction.