What do we know about the Nice killer? 31-year-old Frenchman known to police

Authorities have identified the truck driver in the deadly Bastille Day attack in Nice, France, that killed more than 80 people as a Frenchman who police were familiar with.

Read: 84 Dead In Terrorist Attack At Bastille Day Celebration in France: 'There Was Carnage'

Police say 31-year-old Mohamed Lahouaiej-Bouhlel, a Tunisian-born Frenchman and divorced father of three, was the driver after his ID was discovered inside the vehicle following the massacre.

Lahouaiej-Bouhlel is said to have no apparent ties to any religious extremist group, was living alone in the working class section of Nice.

Mohamed Lahouaiej-Bouhlel, 31, is believed to be behind the Nice massacre. (Photo courtesy of INSIDE EDITION)

His neighbors described him as a loner that kept to himself. One neighbor, Sebastien, told The Guardian that Lahouaiej-Bouhlel did not seem overly religious.

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Other neighbor's told France's BFM-TV that he had become depressed following the divorce of his wife. Some neighbors said prior to the attack he was "depressed and unstable, even aggressive."

According to reports, the driver was on police radar due to his criminal past. Lahouaiej-Bouhlel, who worked as a delivery man, was previously convicted for armed robbery, domestic violence and once fell asleep behind the wheel while working.

Even though he kept a lengthy rap sheet, he was not on any terrorist watch list, according to France's BFM-TV.

Read: Texas Dad and His 11-Year-Old Son Among Nice Victims: 'They Are So Loved'

ISIS has not claimed responsibility for the latest attack in France; however, the terrorist group has praised the actions on social media.

Bastille Day Attack in Nice, France and Aftermath Graphiq

The terrorist organization has often used vehicles during attacks, packing them with weapons and explosives. The group has encouraged this by posting tutorial videos on their website.

French authorities are currently working to see if Lahouaiej-Bouhlel acted alone in the massacre. He was killed by police in the melee and authorities discovered a pistol, large gun and grenades inside the truck.

Watch: Trump Slams Obama on ISIS Threats: 'Nobody Know Why He Doesn't Have More Anger'

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