Frenchman Ziyed Ben Belgacem, who was shot dead by a soldier Saturday at Paris's Orly airport, was ready "to die for Allah" and had vowed to slay others.
The 39-year-old Paris-born Frenchman was killed as he attacked a soldier, grappling with her and trying to steal her assault weapon, ending an hours-long spree of violence.
Ben Belgacem had a string of criminal convictions and showed signs of Islamic radicalisation.
Paris prosecutor Francois Molins described him as "an extremely violent individual" harbouring terrorist instincts and his neighbours said he was a "devil" with a "scary face".
His rap sheet paints a picture of a seasoned criminal, well-used to courts and spells behind bars. He had nine entries on his record, from violence to receiving stolen goods. In 2001, he was sentenced to five years in prison for armed robbery.
This was not his last stint in prison. In 2009, he was handed successive sentences of three and five years for drug trafficking.
While he was in prison, officials noticed "signs of radicalisation", according to prosecutor Molins, and he was known to police but not considered a serious threat. His house was searched, with no result.
The attacker lived on the sixth floor of a building in the northeastern Paris suburb of Garges-les-Gonesse, in the multi-ethnic Seine-Saint-Denis area. Neighbours described him to AFP as a withdrawn, serious man who nobody really knew. He seemed lonely, they said.
No one had any idea of his spells in prison, although since his most recent release from jail in September, he had been under judicial monitoring.
"The last time I saw him was three days ago. He had a determined air, as if he wanted to fight with his family or colleagues," said one neighbour Hamid.
"Sometimes, we'd meet in the elevator, that's all. He always wore sports clothes. He has a scary face, a real devil," said Hatice, another neighbour.