French anti-terror prosecutors said Aoussaoui attacked worshippers in the heart of the Mediterranean resort city with a foot-long blade, slitting the throat of an elderly woman in an apparent beheading attempt.
A mother in her forties also succumbed to her injuries after seeking refuge in a nearby bar.
The Islamist was shot 14 times and wounded by armed police as he screamed “Allahu Akbar” during the attack and “even while under medication” as he was taken to hospital, Nice’s Mayor Christian Estrosi said.
Aoussaoui arrived in Nice at around 6.30am via the railway station, where he quickly changed his clothes, Jean-Francois Ricard told journalists today.
CCTV then showed him arriving in the church at 8.30am and staying there for nearly half an hour.
The assailant, born in Tunisia in 1999, entered Europe via the Italian island of Lampedusa on September 20 and arrived in Paris on October 9. The travel information came from a document on Aoussaoui from the Italian Red Cross, the state prosecutor said.
Investigators found two unused knives, a Koran, two mobile phones in addition to a bag with some personal effects. He was unknown to French security services, Mr Ricard told a press conference.