The 31—year-old of Tunisian descent, who is believed to have been a married father of three, ploughed a truck into crowds of people celebrating the French national holiday in the southern resort city.
The dual national is believed to have been known to police with a history of carrying out crimes including theft and armed attacks but he was not on a terror watch list.
The lorry he was driving began its journey in the hills outside Nice before it was driven down into the centre of the city.
Knowing his home neighbourhood increases the likelihood that police may be able to trace any accomplices who supported him during the attack.
A security source said: “He was known to the police for violence, and using weapons, but had no direct links with terrorism.
“His identity card was found in the lorry. He had French and Tunisian nationality.”
Police are still trying to establish whether the driver had any accomplices in a city with a reputation for Islamist activism.
No group has yet claimed responsibility but the attack has the hallmarks of an Islamic State-inspired killing.