How did alleged Paris attacks planner become radicalized?

BELGIUM -- Of the nine terrorists police say were involved in the Paris attacks last Friday, five are, or were, French.

Suspected mastermind, Abdelhamid Abaaoud, is a citizen of Belgium.

The people of Abaaoud's old neighborhood came out in the thousands Wednesday night in a gesture the jihadist would have hated -- a rally to show solidarity with the residents of Paris.

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Several young men who said they knew Abaaoud described him as "normal."'

"He dressed like me in a tracksuit, a regular young guy," said one man.

As for becoming a jihadi, it means that before that he was a victim of discrimination, another man said.

"People don't get radicalized because they want to -- it's not like a trip to the store," he added.

So how did someone who won a scholarship when he was young grow up to be a terrorist?

Abaaoud was raised in a modest home in Molenbeek. But the dark side of the suburb apparently held more appeal than his family's clothing business.

This undated image taken from a militant website on Monday Nov. 16, 2015 showing Belgian Abdelhamid Abaaoud. AP

He became radicalized during a stint in jail for petty crime.

Released in 2013, he suddenly vanished, and then showed up in Syria.

Under the name Abu Umar al-Baljiki, the Belgian, he started using social media to recruit jihadists.

Abaaoud's career profile shot to real prominence when he appeared in an ISIS propaganda video, dragging bodies behind a pickup truck and reveling in the image it gave him.

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According to intelligence reports, he snuck in and out of Europe to coordinate terrorist attacks.

Abaaoud bragged about in an ISIS online magazine.

Whatever his self-image may have been, residents in his old neighborhood are concerned, Molenbeek already had a bad reputation, now Abaaoud hasn't done it any favors.