The grinning jihadi: Did this 20-something Belgian mastermind the Paris terrorist attacks?

French investigators think they know who masterminded the deadliest terrorist assault in peacetime France: Abdelhamid Abaaoud, a 20-something Belgian who joined the ranks of the Islamic State a few years ago.

The son of a Moroccan shopkeeper, known to the intelligence community for his high-profile presence on social media, Abaaoud is being studied by investigators as the man who orchestrated the seven attacks in the Paris area on Friday that left at least 129 people dead and hundreds more wounded, the prosecutor’s office said. Abaaoud, who Le Monde newspaper says is 28, is also linked by French officials to a failed assault on a Paris-bound high-speed train in August and a plot to attack a church in the city in April.

Belgian security officials began tracking him in March 2014 after he appeared in a video behind the wheel of a pickup truck dragging mutilated bodies to a mass grave in Syria. About six months later, photos surfaced on the Internet indicating he had lured his 13-year-old brother Younes to the war zone.

Like many jihadis, Abaaoud leads a ghost-like existence, with investigators scarcely able to piece together an outline of his whereabouts. His trail went cold in Greece after thwarted assaults against Belgian police in January he’s accused of planning. He’s believed to have returned to Syria.

The Paris attacks were “decided, planned in Syria, organised in Belgium and carried out in France,” President Francois Hollande told lawmakers on Monday in a rare joint session of the two houses of parliament in Versailles, on the outskirts of the French capital.

There are few clues to Abaaoud’s radicalisation. He grew up in Molenbeek, a working-class district of Brussels, where the now-banned Shariah4Belgium extremist group was particularly active in seeking recruits among the disenfranchised and alienated youth. The Guardian reported that he had committed several armed robberies. His father said he was a good son whose actions have brought shame to the family.

“Why would he want to kill innocent Belgians? Our family owes everything to this country,“ Omar Abaaoud told La Derniere Heure newspaper this year. “Abdelhamid was not a difficult child and became a good businessman. Suddenly, he left for Syria. I wondered every day how he became radicalised to this point. I never got an answer.”