His neighbours in the village of Bosc-Roger-en-Roumois were shocked to discover they had a terrorist next door, but they had been aware of his growing radicalisation.
He grew a beard and was seen wearing long djellaba religious robes. He worshipped at the mosque in the nearby town of Elbeuf.
But nobody could explain how he moved from such devout behaviour to become a cold-blooded killer.
Elisabeth Marchand, a careworker in the village, said the young people in Bosc-Roger had nowhere to go. "If you're alone and isolated maybe that's an explanation," she said.
Terrorism and Middle East experts who have studied the rise of Isis can see a pattern in the militant group's recruitment of foreigners.
Many of them, including Britons with Pakistani or Bangladeshi backgrounds, had no knowledge of the Muslim faith before joining Isis ranks. Two British jihadists from Birmingham, Nahin Ahmed and Yusuf Sarwar, took copies of the book Islam for Dummies with them when they went to Syria.
According to one French expert, Jean-Pierre Filiu from Sciences-Po university: "Somebody who knows nothing about Islam is much easier to attract."
Radicalisation via the mosque or prison was no longer the norm. Isis operated like a cult, targeting "an isolated teenager sitting at his screen", said Filiu.
From there, social media, Skype and email provide an easy and confidential route for their terrorist brainwashing.
British MPs who investigated the killing of British soldier Lee Rigby on a London street by two Muslim converts in May last year described social networks such as Facebook as a "safe haven for terrorists".
Their report prompted Prime Minister David Cameron to shift attention to the responsibilities of internet companies - and away from signals missed by British intelligence services.
Filiu says Isis militants treat foreign recruits as the "bottom of the food chain", as one disillusioned Indian jihadist can confirm. Areeb Majeed, a 23-year-old engineering student from Mumbai, said this week that he was "humiliated" by Isis when he was told to clean lavatories in Iraq instead of fight.
Young French jihadists in Syria who want to return home have complained that they were put on washing-up or weapon-cleaning duties.
Le Figaro quoted one who said he was "fed up" because his iPod didn't work in Aleppo.
According to Filiu, the foreigners are brutalised and ordered to use their contacts on Facebook to bring in more recruits. Thousands are travelling to Syria and Iraq from all over the world, including Europe and Australia, and are not sent into battle but are used for propaganda purposes.
So Maxime Hauchard, the convert turned jihadist known as Abu Abdallah el Faransi, is probably not so unusual among the 1132 French nationals who have resorted to jihadist networks.
The Paris prosecutor said last week that Hauchard "is far from an isolated case".
If Hauchard fitted the would-be jihadist profile, said one of his former Normandy neighbours, so might other unemployed youths with time on their hands, who could be given a new sense of pride by taking up weapons in the name of Allah.
