From ABC News:
The driver’s uncle, Sadok Bouhlel, told The Associated Press that given Bouhlel’s family problems — he was estranged from his wife and three children — the Algerian “found in Mohamed an easy prey for recruitment.”
Bouhlel’s rapid radicalization has puzzled investigators. Friends and family said he had not been an observant Muslim in the past. Cazeneuve said Monday on RTL radio that the driver may have been motivated by IS messages but not necessarily coordinating with a larger network.