Death Before Breakfast by George Bellairs
First published in 1962, Death Before Breakfast is a Chief Inspector Littlejohn mystery full of intrigue, mysterious motives, and ingenious speculation. On her way to church early one morning, Mrs. Jump sees a dead body in the gutter in July Street. Frightened, she hurries on, but her conscience convinces her to return, only to find the body gone. Doubting herself, she nevertheless tells her boss, Inspector Littlejohn of Scotland Yard, who decides to investigate further. He soon discovers that July Street is full of unusual people. Everyone has a motive. Everyone is a suspect. From London to Paris and back, Littlejohn unravels the tangled web of connections between this curious cast of characters to expose the murderer.