Henri Landru was convicted of murder and sentenced to death.
Fernande Segret, Landru's last mistress and the one to survive, had told her story in the Arizona Daily Star. She would probably never know if anything Landru told her was the truth. She might never know if she was saved from eventual murder by his arrest.
There were some who did believe he was a spy as he had intimated to Segret.
From the Star, Sunday, Jan. 15, 1922:
Henri Landru, French Bluebeard,
May Have Been Master Secret Agent
Believed by Member of Paris Bar
Murderer of Eleven Women May have Used Them for Obtaining Secrets
Paris, Jan. 14—The idea that Henri D. Landru may have been a master spy who employed as his agents the 10 women he is convicted of murdering has been advanced by Henri Javal, a member of the Paris bar.
This suggestion is advanced in an effort to account for the fact that no direct evidence of the murders was brought out at Landru's trial. The absence of this evidence has caused a feeling of uncertainty by most Parisienes in regard to this mysterious case and numerous attempts have been made to solve the mystery on some other basis than murder.
Developing his theory, Maitre Javal says:
"Eleven persons, 10 fiancees and the son of one of them, have disappeared. Landru alone knows what has become of them, and he says nothing. By his silence he puts his head at stake. This can only mean that the truth, were it known, would be as fatal for him. But the whole affair takes on another complexion if we imagine, for the sake of argument, that his victims were his accomplices in crime, and that crime espionage.
"Let us suppose," he continues, "that during the war Landru was a German spy-recruiting agent. He prefers to work through women. At once this explains his meetings, sometimes five in the same day, with hundreds of women, of whom he chooses only a few, and those few without friends or relatives who might be surprised at their long absence. He takes a lonely villa as far from other habitations as possible where he can receive them. There he fabricates false identity papers for them, keeping their own and sends them forth on their missions of treason. Arrested, Landru says nothing, and his 'victims' naturally do not break the silence.
"Can you imagine, by any other hypothesis," Maitre Javal concludes, "why so careful, calculating a criminal as Landru should burn the bodies of his victims with great difficulty and yet neglect to throw into the all-consuming flames such damaging evidence as their identity papers?
"And does not this theory explain why he should keep such an incriminating document as the diary, in which reference to his victims is made by initials other than their own? He needed their identity papers and the entries in his diary to show to those who employed him as a recruiter of spies."
Whether he was a spy recruiter or a mass murderer, the punishment would be the same. However, if he did recruit spies, sparing his life for a few months in a effort to get more information might be useful.
This was speculation, however, and Henri Landru was executed by guillotine Feb. 25, 1922.
Fernande Segret became a cabaret or opera singer for a while and then taught school in Lebanon. On Jan. 31 or Feb. 1, 1968 — account differ on the exact date — she committed suicide at age 75 by throwing herself into the moat of the Castle Flers. A photo of Landru in her room showed that perhaps she continued to love him despite his crimes.