NICE — There are still more questions than answers three days after Mohamed Lahouaiej Bouhlel drove a 20-ton truck through hundreds gathered to see the Bastille Day fireworks on the city's waterfront, killing 84 people and injuring more than 200, before being shot dead by police.

Still, a portrait of the 31-year-old divorced father of three is emerging, as authorities probe his movements, activities and the people with whom he was in contact in the days and weeks leading up to the attack.

Bouhlel was born in Tunisia but had a permit to live and work in France. He was a delivery driver known to the police as a petty criminal who had run-ins with the law since 2010 for theft and acts of violence, including incidents involving a gun.

Sources tell Nice-Matin that Bouhel had been in the midst of moving houses, which he used as an excuse to justify renting the large truck. The recent DAF model LF was equipped with control devices that provide information on the driver's movements and actions, which investigators have already analyzed to obtain further information on the the routes he took.

These devices and the images from the CCTV footage show that the attacks were clearly planned ahead of time, as Bouhlel had scouted out the famous waterfront Promenade des Anglais on the two days before the attack.

Mohamed Lahouaiej Bouhlel's residential permit — Photo: French national police

The transport company where he worked describe somone who often would forget his keys in the truck or leave the headlights on all night. He was described as "often nervous" and "absent-minded."

One recent action in particular has drawn the attention of investigators. On July 6, Bouhlel transfered 24 euros ($26) to a website, under the heading "Islam" on his bank statement. He was not a religious man, however, these last months, he appeared to have taken a major interest in his Muslim roots. The hard disk of his computer showed that, shortly before the attack, he visited several sites of jihadist propaganda.

Accomplices, ideology

Among the unanswered questions. Did Bouhlel get external help? Did he have accomplices? Was it really in the name of the ISIS terrorist organization?

As has been reported, ISIS has claimed Bouhlel was one of its soldiers, but did he receive a direct order from the terror group, or was he inspired by their ideology?

French Minister of the Interior Bernard Cazeneuve stated that "it seems he became radicalized very quickly." French authorities had never opened a security file on Bouhlel because he had no known ties to any terrorist or jihadist group.

President Francois Hollande said on Friday that it was "an attack whose terrorist nature cannot be denied."

To help find some anwsers, French authorities detained six people in connection with the attacks. Bouhlel's estranged wife was detained at her apartment Friday and released Sunday morning without charge. Henaj, a man who supposedly sold a gun that the driver carried in the truck, along with two replica assault rifles and a dummy grenade was arrested Sunday along with his wife.

Only hours before the Nice attack, Hollande had announced that France's state of emergency that had been instituted after the Nov. 13 attacks in Paris would be removed later this month. After the attack in Nice, Hollande quickly changed course, announcing the special security measures were now being extended for another three months.