At noon on October 31 1946, the body of a 48-year-old woman, Dagmar Petrzywalski, was found by the side of the A20 in Kent. She had been strangled by Sidney Sinclair, a lorry driver from whom she had hitched a lift early that morning on the way to visit her sister.

In "Murder at Wrotham Hill" (Quercus, £18.99), Diana Souhami has reconstructed the murder, examined the lives (as well as the deaths) of Miss Petrzywalski, her killer, the investigating detective, Robert Fabian — the celebrated “Fabian of the Yard”— and the executioner, Albert Pierrepoint, and set them within the context of a country still scarred by the horrors of war.

Dagmar – a nervy spinster who, traumatised by the Blitz, had retired as a telephonist in London — used her meagre pension to buy a hut opposite her mother’s modest home, and subsisted by keeping chickens and growing vegetables.

Her death was completely senseless. Sinclair, aka Harold Hagger, a bigamist, black marketeer and recidivist with a long history of petty crime and violence, had picked her up with the expectation of sex. It seems he had no premeditated desire to kill but, when Dagmar —a virgin — screamed in fear, he strangled her with the man’s vest she had been using as a scarf. To the day of his execution, Sinclair stuck to his story that she had “offered to play about” with him and had been attempting to steal his wallet.

Souhami paints a compelling portrait of a bleak and deprived period in Britain’s history, through the story of two sadly wasted lives. Her only digression is in the chapter about Pierrepoint, the famous executioner.

Here, she catalogues the mass murders at the death camps that led to his biggest commission — the hanging of 226 Nazi war criminals. If there is a parallel to be drawn between a callous killing machine that brutally murdered six million Jews, and the clumsy assault that claimed an innocent life one cold morning in Kent, it is not one Souhami chooses to probe.

The publicity on the book’s jacket asks: “After World War Two, why did one more violent death matter?” It is a question the reader is left to ponder alone.