The Nice lorry attacker did several scouting missions on the Promenade des Anglais before carrying out the deadly Bastille Day attack, prosecutors have revealed.
Mohamed Lahouiaej Bouhlel had been searching online for July 14 celebrations, seemingly planning his attack, which left 84 people dead.
The prosecutor said there was no proof the attacker had direct links to the so-called Islamic State group, but internet searches showed he was interested in radical Islamist movements.
Bouhlel paid €1,600 (£1,330) on July 4 to hire the truck used in the attack and in the days before the massacre he was caught twice on CCTV rehearsing the journey that he would take on July 14, prosecutors said.
French Prime Minister Manuel Valls faced boos and calls to resign as he laid a wreath for the 84 people killed in the lorry attack in Nice.
Hours later Mohamed Lahouaiej Bouhlel drove a 19-tonne lorry down the promenade killing 84 people and injuring 200 more.
France's prime minister stated on Sunday he believed the man behind the Nice lorry attack was radicalised "very quickly"