After their release from jail, they decided to work together to kidnap rich tourists visiting France and steal their money.

De Koven's brother Henry later came to France offering a 10,000-franc reward from his father, Abraham, for information about the young woman.

The next murder came on 3 September, after Weidmann and Million lured Janine Keller, a private nurse, into a cave in the forest of Fontainebleau with a job offer.

Weidmann killed Keller with another fatal shot to the back of the neck, before robbing her body of 1,400 francs and a diamond ring.

On 16 October, Million and Weidmann arranged a meeting with a young theatrical producer named Roger LeBlond, promising to invest money in one of his shows.

Raymond Lesobre, a real estate agent, was shot in the killer's preferred fashion while showing him around a house in Saint-Cloud.

Although they were unarmed, the wounded Sûreté men managed to wrestle Weidmann down and knocked him unconscious with a hammer, which happened to be nearby.

"[1] The murder trial of Weidmann, Million, Blanc and Tricot in Versailles in March 1939 was the biggest since that of Henri Désiré Landru, the modern-day "Bluebeard", 18 years earlier.

The "hysterical behaviour" by spectators was so scandalous that French President Albert Lebrun immediately banned all future public executions.

[2] Chapter "Death On A Quiet Boulevard" in Tom Fallon: "Craftsmen In Crime", published by Frederick Muller Ltd., London 1956.