According to Le Figaro, French Chief Prosecutor Francois Mollen said this.
He also told the terrorist rented the 19 t truck on July 11 and he had to return it on July 13. The police found machine guns, the AK-47, M16 rifle, 7.65 mm gun, bullets and grenades in the truck.
They also found the phone, driver's license, credit card and several documents in the truck cockpit, and eight empty palettes and a bike inside the truck.
According to Prosecutor, the killed terrorist "was not familiar for the intelligence service. He had never shown the radicalization symptoms".