A clearer picture of Omar Ismail Mostefai, one of the Bataclan attackers, is starting to emerge.
Of Algerian origin, the 29-year-old was born and raised in the Parisian suburb of Courcourronnes, where he lived with his large family.
He had been involved in petty crime, arrested eight times, but had never spent any time in prison.
And despite being on the government's radicalisation radar, he had never been implicated in a major investigation.
The BBC's James Longman spoke with a young man, Riza, who lives on the estate and says he knew Omar until around 2009-2010, when he left the area. The last he had heard, Mostefai had a young daughter and had moved to the area of Chartres.
He remembers him as a just "one of the guys" who would spend time racing cars around and hanging out with mates.
"He was a good person. He was the kind of guy who, if you had an issue with a group from another area, would help you out."
Riza said: "We're upset like everyone. It's hard. We never thought he could do this.
"I don't know why he did this. What was going on in his head? I don't know who he was hanging around with.
"He was here like all the other youngsters. Messing around, stupid stuff. But I'd never thought he'd get to this point."
"I'm a bit sad, said Riza. "It hurts. When someone does that and he's from where you are."
Visit to Syria?
Mostefai is understood to have moved an hour south, to Chartres, in around 2009. It was around this time that he was flagged to authorities as a possible radical.
He reportedly attended the Generation 2000 Mosque in nearby Luce.
The president of the mosque said he did not know Mostefai. "We expel people who do not respect our rules or behave strangely, and we report them to the authorities," he told AFP news agency.
French paper Le Monde reported that Mostefai might have left Chartes for several months to visit Syria around January 2014.
According to the paper there are records of his having passed through Turkey around October 2013, before the intelligence services picked up his trail again in early 2014, observing a small group of Salafists in Chartres.
At the time he was considered to be a regular member of the group.