In the loosely autobiographical DEATH IS A LONELY BUSINESS, references to many well-known RB stories are made (including 'Skeleton' & 'The Small Assassin'), without naming them by title. In one scene, the character Crumley (my namesake!) talks about a story by 'Ray' in which a passenger on a train stopped at a station sees a murderer on the other train (opposite).
Does anyone know what story he is referring to, and where the story appears? I always thought it sounded like a cracker, but I wasn't able to work out what story it was.

It could be "The Utterly Perfect Murder".

Or "The Town Where No One Got Off". I always get these two stories mixed up, and still can't remember which is which!

In "The Town Where No One Got Off," the would-be murderer is on the train platform, not a train. "The Utterly Perfect Murder" also features a would-be murderer on a train, but doesn't explain how anyone would know his intentions. In "A Touch of Petulance," a young man meets his older self on a train and learns he is a murderer.

Thanks for the replies. Yes, a couple of those stories did occur to me, but don't really fit the description given in the novel. When I get a chance I'll have to look up the exact quote.